Science Reviewer UPCAT

8/15/2019 Science Reviewer UPCAT

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Definitions of Science An organized body of knowledge gathered over a long period of time to explain the worldwe live in.Knowledge or a system covering general truths or the operation of general laws especiallyas obtained and tested through scientific method.

Scientific Method

1. Identifying the problem ( uestioning!". #athering $reliminary data%. &ormulating a hypothesis'

. )esting of the hypothesis*. Analysis and Interpretation of data+. ,rawing of -onclusion

Independent Variable variable changed by the experimenter Dependent Variable variable that responds to the variable that is changed in the experiment.Experimental group groups that receive treatment.Control group opposite of /xperimental.

hypothesis it is what we think the answer to the 0uestion is and it should stated in termsof the variables defined.

Laws and Theories

*Scientific law a description of a natural occurrence that has been observed many times.

' Scientific theory a reasonable explanation of a scientific law. It is derived from a hypothesisthat has been supported by repeated testing.

' Model helps visualize occurrences and ob ects that cannot be observed directly.

Note: 2cientific laws and theories cannot be proven absolutely. )hey are maintained as allobservations support them.

3easurements

In science4 the metric system is used in all measurements for its convenience andsimplicity.

)he International 2ystem of 5nits (2I! uses the seven base 0uantities and units givenbelow6

Physical Quantity Unit Name (symbol3ass Kilogram4 kg

7ength 3eter4 m)ime 2econd4 s

Amount of 2ubstance 3ole4 mol)emperature Kelvin4 K

/lectric current Ampere4 A7uminous intensity -andela4 cd

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SCIENCE REVIEWER

General Science



A. 8eading 3etric 3easurements

No! of si"nificant di"its # no! of certain di"its $ one certain di"it (% or &

' am)le : )he diagram below is a metric ruler used to measure the length of a pencil. 9ow longis the pencil:

)he smallest fraction of a centimeter in the metric ruler is ;.1 cm. )his corresponds to thelast certain digit in any measurement. )he pointer reads <.; cm. =ne uncertain digit should beadded. In this case it is ;.

+nswer: Len"th of )encil # ,!%% cm

>. -onverting 3etric 5nits

-onversion of metric units is easily performed4

3ega 1; +

Kilo 1;%,eka 1; "

9ector 1;1

>ase unit 1;;,eci 1; ?1

-enti 1; ?"

3illi 1;?%

3icro 1; ?+

' am)le -: .ow many "rams are there in /0!d centi"rams1

)o convert %@.* cg to grams4 count the number of steps from centi to base unit. 2ince itmoves upward4 the movement of the decimal point is to the left.

+nswer: %!/0& "

Ma2or 3e"ions of the 'arth

1. 7ithosphere the solid part and the largest portion of the earth". 9ydrosphere the li0uid part. It covers about @1 of the earthBs surface%. Atmosphere the gaseous portion that envelops the earth

. >iosphere the region where living things are found.

3oc4s and Minerals

/verywhere you look4 you find rocks of different shapes and sizes. Chat is important toremember about rocks is the way they were formed. )he varying conditions for the rock formationinfluence the characteristics that each rock develops4

Igneous rocks formed from hardened magma and lava.e.g. 8hyolite4 #ranite4 >asalt4 etc.

2edimentary rocks form from deposited fragments or particles of other rocks that havebeen weathered and eroded.

e.g. limestone4 conglomerate4 dolomite4 shale

2

8 cm 9 10

Decimal pointmoves to the left

Decimal pointmoves to the

right



3etamorphic rocks rocks that have undergone changes due to heat and pressuree.g. marble (from limestone!4 slate(from shale!

' 8ocks are made up of minerals which are either elements or compounds.

5eatherin" is a term for all processes which combine to cause the disintegration and chemicalalteration of rocks at or near earth surface.

'rosion includes all the process of loosening4 removal4 and transportation which tend to wearaway the earthBs surface.

Lithification is the conversion of unconsolidated sediment into solid rock.

Weather and Climate

Meteorolo"y 6 the study of the earthBs atmosphere4 weather and climate

5eather the daily condition of the earthBs atmosphere

7limate general conditions of temperature and precipitation in a large area over a long period of time.

8ases found in the atmos)here:

a! Nitro"en about @D- nitrogen in air reacts with chemicals to produce nitrates4 which are used by living

things for the manufacture of proteins- is returned to the atmosphere by the process of decay

b! 9 y"en 6 "1used for respirationfor combustion processes

c! 9ther "ases 6 (water ;a)or< 79 - < 9 /

Layers in the atmos)here

1. )roposphere layer where life exists- where different weather conditions prevail- has lowest temperature

". 2tratosphere contains ozone that serves as a protective shield against 5E rays.- where etstream is found

%. 3esosphere layer where meteoroids that enter the earthBs atmosphere are burned.. Ionosphere contains ions that are used for radio communications

*. /xosphere orbit space for artificial satellites.

)he uneven temperature and pressure in the atmosphere result in the movement of air called winds.3onsoons are examples of winds that result from the differences in the absorption andreflection of thermal energy by different materials of /arth.

'colo"y

1. 'colo"y the study of how living things interact with their environment.-! 'colo"ical =actors

a. biotic all living factors in the environmentb. abiotic nonliving factors that are essential to living organisms

/! $opulation a group of the same species living together >! -ommunity all the different populations living together &! /cosystem community of different living things interacting with one another and with their

nonliving environment

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?! >iomes a large area whose ecological communities are determined by its climate.

Solar System

)he probable origin of our solar system4 specifically the sun4 is similar to that of other stars)he age of a star is related to its temperature and its color.@luish and white stars are thehottest and youngest stars. )he least hot and the oldest star are thereddish stars .

Nebular theory states that the solar system originated from a rotating gas and dust cloudcomposed of hydrogen4 helium and some heavier elements.

Ptolemaic Theory 6 )he earth is stationaryF each planet and the sun revolved around theearth.

7o)ernican Theory 6 )his theory considers the sun as the center of the solar system. )heearth and other planets revolve around the sun in a circular orbit.

Planets- 3ercury? 8ocky4 cratered surfaceF extremely thin atmosphere- Eenus?)hick cloud coverF green house effect- /arth?li0uid water4 life- 3ars?polar ice caps4 pink sky4 dominant volcanoes- Gupiter?#reat red spots4 thin ringF huge magnetosphere- 2aturn?many rings and ringlets4 )itan only moon with substantial atmosphere- 5ranus?8otates on sideF worldwide ocean of superheated water - Heptune? 5nusual satellite rotation4 rings4 great dark spot.

+steroids are ob ects that orbit the sun like planets. 9owever they are smaller than the planetsand so they are sometimes called minor planet.

Meteoroids 6 are ob ects smaller than the asteroids that revolve around the sun.

7omet is a mass of frozen materials such as water4 methane and ammonia along with the bits of rock and dust.

Solar ecli)se when the sun4 the moon and the earth are in straight line. ,uring solar eclipse4 thesun canBt be seen from earth because the moon covers it.

Lunar ecli)se same as solar but in this case the sun covers the moon.

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'A7'37BS'S =93 8'N'3+L S7B'N7'

II. 3atch each definition in column > with the correct word in column -.Crite the letter of the correct word and the first letter of the correct word in the space provided incolumn A.

+ @ 7

1. A systematic process of gaining information". A variable that is changed by the experimenter %. It responds to the variable that is changed in the

experiment. A process that results to the breaking of rocks into smaller

pieces*. $rocess by which infrared radiation from the earthBs surface

is absorbed by water vapor and carbon dioxide in theatmosphere

+. It is a description of a repeatable natural occurrence@. A reasonable explanation of natural occurrencesD. A sample group that receives a treatment<. 9elps visualize occurrences and ob ects that cannot be

observed directly1;. An educated guess.11. A change in constitution of a rock brought about by

pressure and heat within the earthBs crust1". 2olid earth materials that have a definite chemical

composition and molecular structure1%. A logical conclusion that can be drawn from an observation1 . )his is done to gather important information before

designing an experiment.1*. A periodic rise and fall of ocean water caused by the moon

and the sun.1+. )he layer of the atmosphere where we live1@. 2easonal wind that blows between continent and an ocean1D. $roduced by the cooling and crystallization of molten lava

or magma1<. $rocess of transporting rock particles

a. 7aw b. )heoryc. 2cientific

methodd. Independent

variablee. ,ependent

variablef. Ceatheringg. Igneous rockh. 8esearchi. )roposphere

j. 3ineralsk.

monsoonl. 3odelm. 3

etamorphismn. )ideo. #reenhouse

effect p. 9ypothesis

. /xperimentalgroupr. Inferences. -ontrol groupt. -onclusion!. /rosionv. 2edimentation". 3

etamorphic rocks#. rocks

II.-omputation1. An adult inhales 1; ;;; 7 of air a day. Chat is the e0uivalent volume in cubic millimeters:". =ne stick of cigarette of a particular brand contains ; mg tar. If a person smokes ";

cigarette sticks in a day4 how many grams of tar does he consume in a week:3. )he nearest star to the sun is ".*" x 1;1% miles away. 9ow far is this in kilometer:

III./ssay

1. Chat is the difference between revolution and rotation:". 5nlike earth4 which is surrounded by sea of gas4 3ercury has no atmosphere. 2tate a

possible explanation for the lack of atmosphere in this planet.

$



@iolo"y 6 the branch of science that deals with the study of living systems and life processes.

+! 7ells)his is probably the most basic term that you would need to know. All living systems are

composed of cells. )hey are the basic unit of structure and fuction in living things. &ollowing is anillustration and concept map of a cell and the different structures contained in it.

7ell

=rganelles are structures with specific functions found within living cells.

Hucleus )his organelle is arguably the most important structure in the cell because itserves as the control center in which individual functions of the other organelles arecoordinated.-ell wall cell membrane the cell wall in plant cells and in some monerans and protestsprovides rigidity for support to the cells and a characteristic shape for functionality andstructure. )he cell membrane on the other hand is selectively permeable.3itochondrion this organelle is also called as Jpowerhouse of the cell . It serves as thesite where A)$s are abundantly synthesized.-hloroplast this serves as the site of photosynthesis among plants and photosyntheticalgae.8ibosome this serves as the site of protein synthesis./ndoplasmic 8eticulum )hese organelles serve as channels or passageways throughwhich materials are transported to the different parts of the cell.-entriole this serves for cytokinetic purposes and is very common among dividing cells7ysosome the structure is also called Jsuicidal bag as it releases digestive uices#olgi apparatus this serves for selection and packaging of cellular materials.

Differences between )lant and animal cellsStructure Plants +nimals

1. cell wall $resent Absent". chloroplast $resent Absent%. centriole Absent $resent

. lysosome Absent $resent*. vacuole =ne large 3any small

%

&ell "all'cell membrane

c(toplasm

n!cle!s

protoplasm

mitochondrion

ribosome

)ndoplasmic retic!l!m

*olgi apparat!sl(sosome

centriole

+icrot!b!les andmicrofilaments

chloroplastExcept for the

Except for the

Biology



.ow did the conce)t of the cell come about1

)he 7ell Theory serves as the basis on which everything that we know about the cell is anchored.)here are three elements to this theoryF1. All living things are made up of cells.". -ells are the basic unit of structure and function in living systems.%. All cells come from preexisting cells.

7ike any biological structure4 the cell is composed of biomolecules that are intricately combined toenable the cell to perform its metabolic functions.

a. -arbohydrates immediate source of energy? elemental composition6 -4 94 =? building blocks6 monosaccahrides? e.g.sucrose (table sugar!4maltose 4amylase

b. &ats 7ipids these molecules serve as another source of energy after carbohydrates? elemental composition6 -4 94 =? building blocks6 fatty acids and a glycerol backbone? e.g. waxes4 oils4 and cholesterol

c. $roteins these molecules serve as sources of building materials.? elemental composition6 -4 94 =4 H4 2? building blocks6 amino acids? e.g. amylase4 actin and myosin

d. Hucleic Acids these molecules include the 8HABs and the ,HABs? elemental composition6 -4 94 =4 H4 $? building blocks6 nucleotides

7ells accordin" to com)le ity

Pro4aryotic cells 6 have no membrane?bound nucleus and organellesF typical of bacteriaand blue?green algae'u4aryotic cells 6 have membrane?bound nucleus and organellesF typical of protests4fungi4 plants4 and animals.

7ell Trans)ort

$assive )ransport does not re0uire the expenditure of energyF moves particles through theconcentration gradient.

Active transport re0uires the expenditure of energyF moves particles against the concentrationgradient.

Diffusion this refers to the process in which molecules of solvent move from an area of highconcentration to an area of low concentration.

9smosis 6 this refers to the diffusion of particles or molecules across selectively permeablemembrane.

7ell 3e)roduction

)his refers to the process by which cells divide to produce daughter cells. It involves either mitosisif somatic or body cells are involves or meiosis if germ or sex cells are involved.

Mitosis refers to the division of the somatic cells- also referred to as e0uational dvision because the ploidy number of the daughter cells is e0ual

to the ploidy number of the dividing cell.

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Meiosis refers to the division of germ cells? also referred to as reductional division because the ploidy number of the daughter cells is

only half that of the parent cell.

@! @otany

$lants are autotrophic organisms capable of synthesizing their own food for growth andmaintenance through the process of photosynthesis. )heir cells are eukaryotic (i.e. with a distinct

nucleus and other membrane?bound organelles! like fungal and animal cells4 but are distinguishedby the presence of cellulosic cell walls4 plastids and large vacuoles. $lant cells may also containnon?living inclusions called ergastic substances that are products of the cellBs metabolism4 likcrystals and starch.

Major plant cell types

)hree ma or plant cell types4 parenchyma4 collenchyma and sclerenchyma4 make up thedifferent tissues of the plant. Although they assume various shapes4 they are most easilydistinguished by general features and location in plant body.

o $arenchyma cells are usually large4 thin?walled and are extremely variable in shape.o -ollenchyma cells have primary cell walls that are thickened irregularly by cellulose and

pectin materials.o 2clerenchyma cells have a comparatively thick primary cell wall bearing heavy depositionsof lignified secondary substance laid down in a laminated pattern.

)issues are aggregate of cells with similar structure and function. 2ome of the cells in thetissue may even undergo further cell modification and change in function. )hus it is difficult toclassify plant tissues on the basis of a single criterion like function4 origin or structure.

o 3eristematic tissues are composed of immature cells and regions of active cell division.)hey provide for growth and are found in the root tip.

o $ermanent tissuesa. /pidermis composed of tiny openings principally on the underside of the leaves that

regulate the exchange of water and gases called stomates.b. $eriderm constitute the corky outer bark of trees.c. Eascular tissues composed of xylem and phloemF xylem functions for the transport of

water and minerals upward from the roots while phloem functions for the transport of food materials.

Different Plant Parts

3ootIt is typically underground organ of the plant axis that functions principally for anchorage

and absorption of water and minerals from the soil. )he first formed root is the primary root. Itdevelops from the radicle of the seed embryo. 2ome root arises from other plant organs like stemsand leaves hence are described as adventitious. )here are two general types of root system4 thefibrous which is found in monocotyledons4 and the taproot4 characteristic of dicotyledons.

Stem)he stem is readily recognized by the presence of nodes. 7eaves are born on these nodes.

)he intervening area between the two nodes is an internode.

Leaf It is a flattened4 green4 lateral appendage that carries out the functions of photosynthesis

and transpiration. -hlorophyll gives the leaf its green color.

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=lowerIt is a modified branch representing the reproductive structure of an angiosperm. It is

generally divided into four parts6 the green sepals4 brightly colored petals4 the male structurstamen4 and the female structure known as pistil (carpel!. /ach of these has a collective term4respectively4 the calyx4 corolla4 andorecium and gymnoecium.

=ruit)he fruit is the ripened ovary with functions to protect and disperse the seeds. It is the

product of the entire pistil and other floral parts that may be associated with it. )wo processesprecede fruit developmentF pollination or the transfer of pollen from the anther to the stigma andfertilization or the fusion of a sperm nucleus and an egg cell.

Photosynthesis and Transpiration

$hotosynthesis and transpiration are physiological processes occurring in leaves.$hotosynthesis involves the trapping of the radiant energy and its conversion into chemical energy.It takes place in the chloroplast of the leaves. )ranspiration is the loss of water in vapor formthrough the stomates4 minute openings distributed on the surface of leaves. A stoma has a pair of epidermal cells called guard cells. Cater moving into the guard cells cause latter to be turgidthereby opening the stomal pore. Chen the water moves out of the guard cells4 these becomeflaccid and the stomal pore closes.

)he numerous stomates of a leaf serve as entry point for a carbon dioxide (photosynthesis!and the exit for water vapor (transpiration!. If transpiration proceeds at a rate much faster that thatof the roots could absorb water from the soil4 the plant tissues suffer from water deficit4 causesplant to wilt.

8eneral 'Cuation:

$hotosynthesis6 + -=" L + 9"= - +9 1"=1" L + ="

3es)iration

- +9 1"=1" L + =" + -= " L + 9"=

? it is a complex process by which energy in the form of A)$ is released from food moleculesingested by organisms.

!lant "axonomy

It is the science of classification4 nomenclature and identification of plats. It is the mostbasic and a unifying field of botany.

-lassification is the arrangement of plants into categories that have similar characteristics.)hese categories called taxa are arranged into hierarchy to form a classification system. )hesmallest taxonomic unit is the species. 2imilar species form a genus and elated genera4 a family.)he most inclusive category4 the kingdom comprises all plants.

Homenclature is the orderly assignment of names to taxa or categories in accordance withthe rules of International code of botanical nomenclature. A plantBs scientific name is a binomiathat is4 it is composed of a generic name (genus! and a specific epithet. )he name of the personwho proposed the binomial completes the scientific name (#ry$a sativa %.&

7! 8enetics

8enetics is the study of heredity and variation..eredity is the transmission of traits fromgeneration to generation while;ariation deals with genetic differences between organisms. )heprocess mainly involved in heredity and variation iscell di;ision!

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)he cells in all organisms grow and reproduce by cell division. A unicellular bacterium4 aftedoubling in size4 can reproduce by dividing into two cells. In multicellular organisms like maincrease in size is attained by dividing its constituent cells.

'ene (egregation and Interaction

Dominant +llele alternative trait that is expressed in the phenotype.

3ecessi;e +llele alternative trait whose expression is marked in the phenotype.Law of Dominance 6 state that only dominant alleles are expressed in the phenotype and thatrecessive alleles are masked among hybrids but are manifested among pure breeds.

Law of 7o dominance states that two e0ually dominant alleles are e0ually expressed in thephenotype and that no blending is achieved.

Law of Bncom)lete Dominance states that among multi?allelic traits4 two dominant alleles thatare not dominant enough to mask the expression of one another4 are incompletely expressed in thephenotype4 hence a blended trait is achieved.

Mendel s law may be separated into two rules6 first4 the law of Independent 2egregation of Allelesand second4 the 7aw of Independent Assortment.

' Law of Bnde)endent Se"re"ation states that the alleles in a gene pair separate cleanly fromeach other during meiosis.' Law of Bnde)endent +ssortment states that the alleles of the different genes separate cleanlyfrom each other and randomly combining during meiosis.

)hese laws can be illustrated using monohybrid and dihybrid cross6

a. 3onohybrid -ross

=ne of the pairs of alternative characters in sweet peas studied by 3endel wa0s round vswrinkled seed. )hese distinctive characters or traits are called)henoty)e while the gene or genetic content coding for these traits is the"enoty)e . In example below4 both parents arehomoEy"ous so that the round ($1! and wrinkled ($"! parents have the 88 and rr genotypes4respectively. )he gametes produced after meiosis by $1 is 8 and by $" is r so the progeny of thefirst filial generation (&1! haveheteroEy"ous (8r! genotypes. 2ince 8 is dominant over r4 then the&1Bs have round phenotype. )his is an example ofcom)lete dominance . 8 masks the expressionof r. )his is thedominant allele. )he allele that is masked ( r ! is therecessi;e .

&emale $arent ($1! 3ale $arent ($"!

$henotype6 8ound Crinkled#enotype 88 rr #ametes 8 r

&ertilization

&1 genotype6 8r $henotypeF 8ound

)o demonstrate that the &1Bs are heterozygous4 a testcross can be conducted wherein the&1 plants are crossed to the homozygous recessive parents (rr!. )he recessive parent contributes

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the gametes ( r ! while the other parent contributes 8 and r. )estcross results in 1 8r (round!6 1 rr (wrinkled! or 161 segregation ratio.

8r x rr

#ametes r 8 8r (round!r rr (wrinkled!

#enotypic 8atio6 18r 6 1rr $henotypic 8atio6 1round 6 1 wrinkled

b. ,ihybrid -ross

)he members of gene pairs located on different homologous chromosome segregateindependently of each other during meiosis.

3endel studied two phenotypes4 texture and color of seeds with two alternative traitsFround and yellow seeds vs. wrinkled and green seeds. 9e crossed pure breeding round4 yellowseeded plants with pure breeding wrinkled4 green seeded plants. )he &1 progenies were all yellowround seeded plants. )he &"Bs gave %1* round4 yellow6 1;1 wrinkled yellowF 1;D round4 green a%" wrinkled4 green plants. Approximately <6%6%61.

)he method used in getting the genotypic ratio among &" progeny is called $unnett20uare or -heckerboard method.

Molecular )asis of *eredity

)he first part dealt with the physical basis of heredity the chromosomes. -hromosomesare the carriers of the multitude of genes. #enes or hereditary units4 on the other hand4 are actuallyfragments or portions of thedeo yribonucleic acid or DN+!

A chromosome is made up of one very long ,HA packaged with histones to fit inside a

minute nucleus of the cell. /ukaryotic cells with several chromosomes would4 therefore4 containmore than one molecule of ,HA. $rokaryotic cells and viruses generally possess one longmolecule of ,HA either naked or associated with proteins but not as organized as compared toeukaryotic chromosomes. )he ,HA has been tagged as the genetic material of all organisms withthe exception of some viruses withribonucleic acid or 3N+ as their genetic material.

Central Dogma of Molecular )iology

,HA as the genetic material is capable of transmitting biological information from a parentcell to its daughter cells and4 in a broader perspective4 from one generation to another. )heinformation stored in its base se0uence is copied accurately byre)lication . 8eplication is aprocess of faithfully copying a ,HA to produce two ,HA molecules identical to the parent ,HA.

)hese ,HA molecules are then passed on to the daughter cells via the chromosomes during celldivision.

)he information stored in the ,HA when expressed will result to a particular trait of anindividual. )he trait is expressed through the action of proteins either directly or indirectly.

)he central dogma of molecular biology consists of three general processes namely6re)lication (,HA synthesis!4transcri)tion (8HA synthesis! andtranslation (protein synthesis!.)he transfer of information from cell to cell or from generation to generation is achieved byreplication. =n the other hand4 the transfers of information from the ,HA to the proteins involve twoprocesses6 transcription and translation. #enerally4 all organisms follow this mode of transferexcept for some viruses that undergore;erse transcri)tion .

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DN+ 3N+ P39T'BN

Mutation 6 changes in the genetic materials that are essentially heritable.

a. ,eletion refers to a segment of base pairs in the ,HA that is spliced off.b. 2ubstitution refers to a segment of the base pairs in the ,HA that is replaced by a differentseries of base pairs.-. )ranslocation refers to segments of base pairs that are differently positioned.d. insertion refers to base pairs that are added to segment of ,HA.

';olution 6 this process refers to the gradual change in populations through time.

D! +nimal De;elo)ment ( +, minutes

-nimal Cells "issues and "issue #rgani$ation

Animal tissues are generally classified into four categories6 /pithelium4 -onnective )issue43uscle and Herve. )hese animal tissues make up all the organ systems of the body.

o /pithelium4 in its simplest form4 is composed of a single continuous layer of cells of thesame type covering an external or internal surface.

o -onnective )issue4 has the widest range encompassing the vascular tissue(blood andlymph!4 -) proper4 cartilage and bone.

o 3uscular tissue consists of elongated cells organized in long units of structures calledmuscle fibers or muscle cells. )he two general categories of muscle4 smooth and striated.2triated or skeletal muscle functions for voluntary control while smooth muscle functionsfor involuntary contractions.

o )he nerve cells or neurons comprising the nervous tissue each possess a cell body whichcontains the nucleus and the surrounding cytoplasm. )he process come in contact withother nerve cells4 or with other effector cells through a point of contact called synapse.

-nimal Development

Animal development is a series of events that is controlled by the genetic information in thenucleus and factors in the cytoplasm. It starts with fertilization and ends into the arrangement of cells which gives the embryo its distinct form. &eatures which are uni0ue to organism such as theshape of the face4 location and number of limbs and arrangement of brain parts are molded by cellmovements in response to the action of genes in the nucleus and molecules in the cytoplasm.

(tages of Development

a. 'ametogenesis

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everse

ranscription

ranslation



/ach species has its own chromosome number. 2omatic cells of humans have "% pars of chromosomes ("" pair somatic and one pair sexF one chromosome of each pair is originally derivedfrom the father and the other from the mother. )he chromosomal pair comes in contact with eachother and exchange segments during meiosis. )his phenomenon provides combinations of parental traits hence there is more viability in the characters of the offspring.

#ametogenesis changes the diploid cells into haploid sperms and ova. -ells undergomeiosis4 a se0uence of two divisions during which the chromosomes divide only once. )he

resulting cells have only half the number of the chromosomes of the parent cells. )his processprevents doubling of the chromosomes during fertilization.

)he male germ cells4 initially round and large4 are changed into slender and flagellatedcells. )he cytoplasm is practically lost and mature cells develop a head4 neck and tail. )he femalegerm cells gradually increase in size as a result of growth.

b. &ertilization

)he ovum and the sperm unite thus restoring the diploid chromosome number of thespecies. In humans4 each gamete has "% chromosomes (haploid!. 5pon fertilization the zygoteac0uires + chromosomes. At this stage of development4 the genetic sex of the individual isestablished.

c. -leavage

)he unicellular zygote undergoes cleavage characterized by active mitoses. It is not aperiod of growth but a time in which the zygote is divided into a large number of small cells4 thblastomeres. /ach blastomere nucleus has the same ,HA since these are derived from the samecell4 the zygote. -leavage ends with the formation of the multicellular organism.

d. >lastula

)he mass of blastomeres forms a hollow fluid?filled cavity4 the blastocoel. In frogs4 cellbelow the blastocoel are largeF these are the macromeres.

In humans4 at this embryonic stage4 the %"?cell cell blastocyst burrows into the uterus. )heblastocyst has two distinct cell typesF an inner cell mass and an outer shell4 the trophoblast. )heformer will become the embryo4 the latter will give rise to the extra?embryonic membranes termeamnion and chorion.

e. #astrula

#astrulation4 a stage of extensive cell movements4 rearranges the embryonic cells. -ellsare translocated to the different areas thus ac0uiring new neighbors and new positions. )heneighbor cells may act as inducers in the formation of structures. )he different cell movementsestablish the third germ layer4 the mesoderm.

At the end of gastrulation4 the embryo has three primary germ layers6 an outer ectoderm4an inner endoderm and middle mesoderm. At this stage tissues have become committed to form

one type of organ? a brain or stomach.)he ectoderm gives rise to the epidermis of the skin4 sense organs and the nervous

system. )he endoderm gives rise to the organs of the respiratory and digestive systems. )hemesoderm gives rise to the organs of the circulatory4 skeletal4 muscular4 excretory and reproductivsystems4 connective tissues and linings of body cavities.

f. Heurula

)oward the end of gastrulation4 the ectoderm along the dorsal surface elongates to form alayer of columnar cells4 the neural plate. )his region thickens and moves upwards forming theneural fold which then fuse to form a hollow tube4 the neural tube. -losing of the neural tube starts

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at the head region and continues posteriorly. )his piece of tissue gives rise to skin pigments4nerves and the adrenal medulla.

g. =rgan formation

)he ectoderm4 mesoderm and endoderm formed in the gastrulation are the sourcematerials for the development of organs. At this stage the component cells are still undifferentiatedand do not show any adult feature. )hese masses are further subdivided into groups of cells until

the organ ac0uires its uni0ue characteristics and specific location.

h. >rain &ormation

)he earliest form of the brain is the nueral tube. At this stage4 the brain shows threeregions? prosencephalon (forebrain!4 mesencephalon (midbrain! and the rhombencephalon (hindbrain!. 7ater4 the prosencephalon divides into telencephalon and diencephalons. )hemesencephalon remains undivided.

In frogs4 the brain is a straight tube and remains in that condition in adult. In humans4 theembryonic brain undergoes bending and twisting. 9ence in adult4 the hindbrain is ad acent to theforebrain and the eyes become anterior to the nose.

i. 7imb &ormation

7imbs start as buds at the embryonic sides4 which later develop as paddle?like extremities.7ater4 circular constrictions appear dividing the limb into three main segments. &ingers and toesdevelop when cells at the most distal end die. )he upper limb rotates <;M sideward so that thethumbs move sideward. )he lower limb rotates <;M towards the center4 placing the big toe at thecenter.

'! 'cosystem and 'colo"y

)he branch of biology that pertains specifically to the relationship of an organism with thatof its environment is known asecology. /cology is a body of knowledge that covers the economy of nature. It involves the study of overall relationship of an organism to its inorganic organienvironment4 that is4 the physical worldF and its relation and interaction with other organisms4 bplants and animals alike.

)he basic functional unit and the most important concept in ecology is the ecosystem4 as itincludes both plants and animals and the physical environment4 each of which influencing theother. /cosystem or ecological system may refer to biotic assemblage of plants4 animals4 microbesinteracting among them and with that of the physico?chemical environment.

Components of the Ecosystem and "rophic %evels

)he ecosystem has two basic components the biotic (living! and abiotic (non?living!components. )he biotic component is further subdivided into two units4 namely4 the autotrophs (selnourishing self feeding! and the heterotrophs (other feeding!.

)he autotro)hs are usually chlorophyll?bearing organisms4 that are able to harness solar energy. In the presence of water and carbon dioxide4 they convert this energy into (chemically?stored energy! known as adenosine triphosphate or A)$. )hey assume the role as producers in anecosystem. $lants are the typical producers. 9owever4 in a0uatic systems4 algal communities or phytoplanktons may be the producers.

.eterotro)hs 4 on the other hand4 are those that depend on the producers as food. )heyare generally classified as consumers4 although those that secure food directly from the producersare better known as herbivores or primary consumers. A secondary consumer or carnivore4 on theother hand4 derives its nourishment indirectly from the producers by devouring the herbivore. Insome ecosystems4 tertiary consumers exist. =ther heterotrophs include also the decomposers

14



where organic matter is reduced to simpler substances. 2tructurally therefore4 the ecosystem cancomposite the following4 that is4 the abiotic factorsF the producersF the macroconsumerF and tdecomposers.

)he abiotic com)onent 4 on the other hand covers climatic4 edaphic (soil! and topographicfactors.

7limate includes light4 temperature4 precipitation and wind. 7ight influences the biotic

components in many ways4 as in photosynthesis4 flowering seed dormancy4 leaf senescence4nesting4 migration and hibernation. 7ight 0uality penetrating with increasing water depths alsodetermines the type of producers (i.e. green algae in shallow water and red algae at greater depths!. )emperature affects living organisms by influencing their metabolic processes. It candetermine the type of vegetation in different ecosystems depending on its availability.

5ater as the universal solvent plays an important role in the ecosystem as it serves as amedium for biochemical processes. It can determine the type of vegetation in terrestrialecosystems depending on its availability. In a0uatic ecosystems4 however4 what plays importantroles are salinity4 ph4 temperature and dissolved oxygen.

The atmos)here is a ma or reservoir of nutrients important to life. Hutrient cycling in theatmosphere is further facilitated by wind. )he latter also accelerates evapo?transcription ratecausing damage to plant structures. 9owever4 it plays an important role in facilitating seeddispersal and in the distribution of plants and animals.

@iome is a geographical unit uniformly affected by a common prevailing climate havin a similarflora and fauna.

Terrestrial biomes the world over include6)ropical rainforests which have the highest species diversity-oniferous forests which harbors the pine?trees,eserts characterized by very low species diversity#rasslands also variously called savannahs4 steppes and scrubs)aigas and)undras?characterized by permafrosts

+Cuatic biomes on the other hand include63arshlands7akes2eas and oceans and/stuaries

=i;e Fin"doms

Monera prokaryoticF unicellularF includes the bacteria and the cyanobacteria.Protista 6 eukaryoticF unicellular colonialF includes the flagellates4 the ciliates4 thsarcodines and the algal systems.=un"i 6 eukaryoticF unicellular (yeasts! and multicellular (molds and mushrooms!.Plantae 6 eukaryoticF multicellularF+nimalia 6 eukaryoticF multicellularF includes the invertebrates and vertebrates.

/cological 8elationships

a. 3utualism Jgive and take relationshipb. -ommensalisms? a relationship where the commensal is benefited and the host is neither

benefited nor harmedc. $arasitism a relationship where the parasite is benefited and the host is harmedd. -ompetition neither organism in this relationship is benefitede. $redation a relation where the predator is benefited and the prey is harmed

1$



=ood 7hain

)hree components of a &ood -hainsa. $roducers occupies the 1st trophic levelF composed of plants and photosynthetic algaeb. -onsumer

- herbivore occupies the "nd trophic levelF 1M consumer - carnivore occupies the %rd trophic levelF "M consumer - omnivore occupies either the "nd or %rd trophic levels.

c. ,ecomposer the last component of a food chain'ner"y Transfer energy is transferred from one trophic level to another following the 1; rule.

=ood 5eb it is a feeding relationship that is illustrative of a series of interlinking food chains.

Ecological %aws

)wo ecological laws can demonstrate this relationship between organisms and their environment. )hese include%iebig/s %aw of Minimum and (hellford/s %aw of "olerance .

• %iebig/s %aw of Minimum states that Jgrowth and survival of an organism isdependent primarily on the nutrients that are least available. JA plant will grow and

develop well where a particular nutrient critical for growth and survival is found tobe inade0uate or not available at all in that particular area. )ake note thatmagnesium is an important component for the production of chlorophyll4 being thecentral atom of pigment.

• (hellford/s %aw of "olerance states that Jthe existence of the organism is within thedefinable range of conditions. )his means that J organisms then can live within arange between too much and too little . )hus an organism han an optimum rangeof conditions (peak! curve and an intolerance zone4 where number of organisms isat its lowest or zero.

7hemistry ? is a science that studies matter4 its properties4 structure and the changes it undergoestogether with the energy involved.

@ranches of 7hemistry+nalytical 7hemistryPhysical 7hemistryBnor"anic 7hemistry9r"anic 7hemistry@iochemistry

Scientific method ? a systematic approach procedure in investigating natureF a combination of observations4 experimentation and formulation of laws4 hypotheses and theoriesF an organizedapproach to research

1%

Chemistry



ST'PS BN + S7B'NTB=B7 M'T.9D

1. =bservation or ,ata #athering=bservations?things perceived by the sensesF can be 0uantitative or 0ualitative

ualitative consist of general observations about the systemuantitative consist of numbers obtained by various measurements of

the system/xamples6

Ice floats in water Einegar is sour >ody temperature is %<.;o- An ob ect weighs 1.* kg

=bservation vs. InferenceInference interpretation of the observatione.g. )he clouds are dark. (observation! It might rain. (inference!

". Are the observations answerable by any natural law:

7aw (natural law! ? a pattern or consistency in observation of natural phenomenaF a verbal ormathematical statement which relates a series of observation

e.g. 7aw of -onservation of 3ass 7aw of )hermodynamics

%. ,efining a problem

. &ormulate a possible solution (9ypothesis 3aking!

9ypothesis? an educated guess to explain an observationF a tentative explanation of a natural lawbased on observation

*. /xperimentation? Is the hypothesis really the answer to the problem:

1,



+. Interpret results.

@. #enerate a generalization.

)heory? a hypothesis that survived testing through experimentationF a model or a way of looking anature that can be used to explain and make further predictions about natural phenomena

Laboratory 3ules and TechniCues

,o not return extra chemicals to the main supply unless so directed. )o avoid waste4 takefrom the supply only the amount of material needed.$erform experiments with the apparatus at armBs length from the body never directly underthe face.If you must smell a substance4 hold the container at a distance and4 with a cupped hand4waft the fumes toward your nose.Hever use cracked or broken e0uipment. It can complete its breaking.Hever pour water into concentrated acid. Always add the acid to the water with stirring.8ead the lower meniscus of a colorless li0uid at eye level. 5se the upper meniscus whenthe li0uid is colored.Hever weigh hot substances.

Measurements in 7hemistry

3ules on the Use of Si"nificant =i"ures

N9N G'39 DB8BTS All non?zero digits are significant

G'39S BN M'+SU3'M'NTS)here may be some confusion about the zero in a measurement. 8ules will be used to

determine whether zeros are significant or not.

1. )railing Neros&inal zeros after a decimal point are always significant.

e.g. "*.%%; g has * significant figures

". -aptive NerosNeros that are found between any two non?zero digits are significant.

e.g @;+.% mm has significant figures

%. 7eading Nerosa. Neros before a decimal point are not significant.

e.g ;.@D+ g has % significant figures.b. Chen there are no digits before a decimal point or when the digit before a decimal pointis zero4 the zeros after the decimal point preceding other digits are not significant.

e.g. ;.;;;* % cm% has % significant figures

. &inal Neros in a whole number may or may not be significant.)o resolve this4 use of exponential is recommended.

'A+7T NUM@'3S Any number that is exact such as the number % in the statement Jthere arethree feet in one yard is said to have unlimited number of significant figures.

+DDBTB9N +ND SU@T3+7TB9N)he sum or difference should have the same number of digits to the right of the decimal

point as the factor with the least number of digits to the right of the decimal point.

e.g. %*.<D+

18



L +@*.D*+@.%D%<1"@<.1+<< 1"@<." (five significant figures!

MULTBPLB7+TB9N +ND DBHBSB9N)he result obtained by multiplication and or division must have the same number of

significant figures as the factor with the least number of significant figures.

e.g (% .+!(% *;.;! % * O% +.;; % + (three significant figures!3UL'S =93 39UNDBN8 9== NUM@'3S Chen the answer to a calculation contains too many significant figures4 it must be roundedoff to the proper number of significant figures. )he rules for rounding off is summarized as follows61. If the digit to be removed is less than *4 drop this digit and leave the remaining numbersunchanged. )hus4 1."% becomes 1." when rounded off to two significant figures.

". If the digit to be removed is e0ual to or greater than *4 drop this digit and increase the precedingdigit by one. )hus4 %. + becomes %.* when rounded off to two significant figures.

+77U3+7I +ND P3'7BSB9N Accuracy refers to the nearness of a value to the true or actual value.

measured by percentage error /rror the difference between a measured value and the true (or most probable! value.

error O Average value )rue value x 1;; )rue value

9igher error4 less accurate

$recision indication of the agreement among different measurements of the same event. measured by deviation

,eviation absolute value of the difference of the measured value from the average value

,eviation O 3easured value Average value

9igher deviation4 less precise

M+TT'33atter? anything that has mass4 takes up space (volume! and possesses inertia

$ure 2ubstance? homogeneous matter that cannot be separated into its components by physicalmeansF with fixed composition and distinct properties

)ypes of $ure 2ubstances6

19

Matter

Pure substances Mixture

Elements

Compounds Homogeneous

(Solution)

Heterogeneous



a. /lements? pure substance composed only of 1 type of atomF cannot be decomposed by ordinarymeans into simpler substances (/x. 94 9e4 Au4 C!

b. -ompounds? two or more elements chemically combined in a definite and constant proportion(/x. K-l4 -9%-==94 3g-l "!

Ionic -ompounds2tructural units are the cations and anions

In the solid state4 the ions do not move from their positions in the lattice but only vibrate inplace

$roperties of Ionic -ompounds3elting $oint6 9igh/lectrical -onductivity6 2olid Hon?conducting

3olten -onducting A0ueous -onducting

9ardness6 Eery 9ard3alleability6 >rittle

-ovalent 3olecular 2ubstances5ncharged or neutral structural units (molecules! in the crystal lattice.

)he atoms in each molecule are held together by strong -=EA7/H) >=H,2.$roperties of -ovalent 3olecular -ompounds

3elting $oint6 7ow/lectrical -onductivity6 2olid Hon?conducting

3olten Hon?conducting A0ueous Hon?conducting

9ardness6 2oft3alleability6 >rittle

-ovalent Hetwork 2ubstances)he structural units that occupy the lattice points in the solid are A)=32.)he atoms are bound to each other by strong -=EA7/H) >=H,2.

$roperties of -ovalent Hetwork 2ubstances3elting $oint6 Eery high/lectrical -onductivity6 2olid Hon?conducting (except graphite!

3olten Hon?conducting A0ueous Insoluble

9ardness6 Eery 9ard3alleability6 >rittle

3ixture? combination of different substances in variable proportionsF can be separated into itscomponents by physical methods of separation

)ypes of 3ixtures6a. 9omogeneous? uniform composition and properties throughout a given sample4 but compositionand properties may vary from one sample to another (e. g. solutions!

b. 9eterogeneous? with non?uniform properties throughout a sample where components retain their identity and phase boundaries exist (e.g. colloids4 suspensions!

=ther -lassification of 3atter a. $hysical 2tates of 3atter ($hases of 3atter!

2=7I, rigid4 has definite volume and shape7I 5I, fluid ( has ability to flow!4 takes the shape of the portion of the container theyoccupy#A2 fluid4 expands to fill up its container

20



b. 2pecial forms based on arrangement of particles and the degree of cohesiveness-rystalline solidsF amorphous solidsF li0uid crystals

-rystalline solids high degree of cohesiveness and very orderly arrangement of particles Amorphous non?crystalline solids disordered arrangement of particles but with a highdegree of cohesiveness7i0uid crystals medium degree of cohesiveness and very orderly arrangement of particlesF allows a degree of ordered motion of particles

P39P'3TB'S 9= M+TT'3

' tensi;e Pro)erties properties that depend on the amount of material observede.g. mass4 volume4 texture

Bntensi;e Pro)erties properties that does not depend on the amount of material observede.g. density4 odor4 taste' trinsic Pro)erties properties that can vary with different samples of the same material

e.g mass4 volume4 sizeBntrinsic Pro)erties properties which are inherent to the substance and do not change for different samples of the same substance

e.g. density4 boiling and melting points4 odor4 tastePhysical )ro)erties characteristics observed or measured without changing the identity or composition of the material7hemical Pro)erties characteristics observed or measured only by changing the identity or composition of the materialF ability or inability of matter to undergo a change in its identity composition at given conditions

7han"es in Matter

Physical 7han"e changes in the phase or state of a substance but not its compositione.g. changes in state (li0uid gas!4 shape or size (granules powder!

$hase -hange determined by existing conditions of temperature and pressure

21

Properties ofMatter

Extensive/Extrinsi

c

Physical Chemicalntensive/ ntrinsic

Changes in Matter

Physical Change ChemicalChange

Phase Change

Solid !i"uid #as

Synthesis

$ecomposition

Single$isplaceme

nt

$ouble$isplacemen

t



2ublimation 2olid to #as ,eposition #as to 2olid3elting 2olid to 7i0uid &reezing 7i0uid to 2olid/vaporation 7i0uid to #as -ondensation #as to 7i0uid

7hemical 7han"e substances are converted into other substancese.g. rusting of iron4 burning of wood

Ty)es of 7hemical 3eactions

1. 2PH)9/2I2 -=3>IHA)I=H formation of a bigger compound from simpler ones A L > L - Q ,

". ,/-=3$=2I)I=H ? A single compound is broken down to " or more simpler substances? 2olids re0uire heat (∆!

A > L - L , L Q

%. 2ingle ,isplacement? -ation or anion is replaced by an uncombined element A> L - A- L >

. ,ouble ,isplacement 3etathesis /xchange of partners A> L -, A, L ->

=ther types6-ombustion ? 8eaction with =" to form -="4 9"=4 H" and oxides of any other elementspresent$recipitation ? &ormation of a precipitate when a solution is added to another $recipitate an insoluble or slightly soluble solid that forms when " solutions are mixed.

2olubility 8ules1. All nitrates are soluble.". All acetates are soluble.%. All H9L salts are soluble.

. All salts of #roup 1 are soluble.*. All chlorides are soluble except chlorides of 9g"

"L4 $b"L and AgL.+. All bromides are soluble except bromides of 9g"

"L4 $b"L and AgL.@. All iodides are soluble except iodides of 9g"L

4 9g"

"L4 $b"L and AgLD. 3ost sulfates are soluble except #roup "4 $b"L and 9g"L.<. All phosphates are insoluble except H9L and #roup 1.1;. All chromates are insoluble except H9L and #roup 1.

Heutralization ? 8eaction between an acid and a base forming water and salt

7AC2 =& -9/3I-A7 -=3>IHA)I=H1. 7aw of -onservation of 3ass

Antoine 7avoisier (1@ %?1@< ! ? J&ather of -hemistry/stablished chemistry as a 0uantitative science2tudied combustion

JIn a chemical reaction4 the total mass of the starting materials (reactants! is e0ual to the total massof the materials produced (products!.

". 7aw of ,efinite $roportion or -ompositionGoseph $roust (1@* ?1D"+!

2howed that copper carbonate always has the ff. proportion by mass6*.% parts -u 6 parts = 6 1 part -

JAny sample of a pure chemical substance contains the same elements in the same definiteproportion by mass of its elements.

%. 7aw of 3ultiple $roportionGohn ,alton (1@++?1D !

22



JIn different compounds of the same elements4 the different masses of one element that combinewith a fixed mass of the other element are in the ratio of small whole numbers.

9I2)=8I-A7 ,/E/7=$3/H) =& A)=38ree4s (>%% @7

o 3atter was composed of fundamental substances6 &I8/4 /A8)94 CA)/84 AI8Leuci))us and Democritus (&th @7

o &irst to propose that matter is made up of tiny indivisible particles called Jatomosmeaning indivisibleLucretius and the 8ree4s ( @7

o Chat appears as a solid ob ect may actually consist of small particleso )here must be some limit to the number of subdivisions which can be formed on

any bit of matter o 3atter can be resolved ultimately into a unit which is indivisible and indestructible

J+T9M means cannot be cut destroyed? )he #reeks were only concerned on the existence of the atom but not on its nature

D+LT9N S +T9MB7 T.'93IGohn ,alton (1@++?1D !

In 1D;D4 published the book JA Hew 2ystem of -hemical $hilosophy wherein hepresented the atomic theory in detail.

,altonBs >illiard >all 3odelThe atom is a tiny< hard< indestructible s)here!

Dalton s +tomic Theory%& 3atter consists of tiny particles called atoms which are indestructible.'& All atoms in a given element are identical and have the same mass.

& Atoms of different elements have different properties.& 8eactions involve only the rearrangement of atomsF separation or union. Chen atoms

combine to form compounds4 the ratio of the no. of combining atoms is fixed.

Thom)son s 3aisin @readJ Plum Puddin" ModelGoseph Gohn )homson (1<; !2tudied cathode ray tubes

)he cathode rays are repelled by the negative pole of a magnetic field)his suggests that the ray consists of a stream of negatively charged particles All atoms must contain electrons.

23



An atom is a diffuse4 spherical cloud of positive electrification with randomly embeddenegatively charged electrons.

)homson measured the charge to mass ratio of the electron6e m O ?1.@+ x 1;D c g

9e also showed that whatever metal is used as a cathode and whatever gas is presentinside the tube4 the cathode ray consist of the same particles as shown by the same e mratio.

Bm)ortance of Thomson s ' )erimentIt correctly suggested that the atom consists of an arrangement of L and charges.It postulated the presence of the electron in all matter

3obert Milli4an ( ,%,5sing oil drop experiments4 he determined the charge of an electron6

?1.+ x 1;?1< c)hus the mass of an electron is (using e m ratio!6

<.11 x 1;?"D g

3utherford s Nuclear +tom Model (+l)ha Scatterin" ' )eriment/rnest 8utherford (1D@1?1<%@! and 9ans #eiger (1DD"?1< *!

3a ority wereundeflected2ome were slightly

deflected

&ew bounced off

/xplanations6

3ost of the mass and all the (L! charges on anatom are centered in a very small region calledthe nucleus.)he atom is mostly empty space.)he magnitude of (L! charge is different for different atoms./lectrons move around the (L!nucleus.

24



'u"ene 8oldstein ( K&% ,/%#oldstein4 in 1DD+ identified the positively charged particle and named it proton

9e used cathode with holes and observed rays passing through the holes opposite indirection to those of the cathode rays.

)he mass of this particle almost the same as the massof the 9 atom

)he charge is e0ual in magnitude (but opposite in sign tothat of the electron!

@ohr s Solar System Model of the +tomHeils >ohr (1DD*?1<+"!

In 1<1%4 tried to explain the line spectra of hydrogen=eatures:

)he electrons move about the nucleus in certain circular orbits.=nly certain orbits and energies are allowed.)he electron can remain in an orbit indefinitely.

In the presence of radiant energy4 the electron may absorb /and move to an orbit with higher /Quantum or 5a;e Mechanical Model

7ouis de >roglie (1D<"?1<D@!4 /rwin 2chrodinger (1DD@?1<+1!4Cerner 9eisenberg (1D@<?1<@+!

=eatures:)he energy of the electron is 0uantized. )he electron moves in %?, space around the nucleus but not in an orbit of definite radius. )he position of the electron cannot be defined exactly4 only the probability.

.eisenber" Uncertainty Princi)le/ )here is a fundamental limitation to ust how precisely we can know both the position and

the momentum of a particle at a given time.The Nature of Li"ht? 8adiant energy that exhibits wavelike behavior and travels throughspace at the speed of light in a vacuum. It has oscillating magneticand electric fields in planes perpendicular to each other.

Primary 7haracteristics of 5a;e1. CAE/7/H#)94 R

? distance between two consecutive peaks or troughs in a wave". &8/ 5/H-P4 ν

? number of waves or cycles per second that pass a given point in space

8elationship of R and ν Rα 1 S or RS O c

Chere cO speed of light (".<<@< x 1;D m s!

Atomic 2pectra? )he spectra produced by certain gaseous substances consist of only a limited number of colored lines with dark spaces between them.? )his discontinuous spectra.? /ach element has its own distinctive line spectrum? a kind of atomic fingerprint.

3obert @unsen ( K K,, and 8usta; Firchhoff ( K-> KK0/ ,eveloped the first spectroscope and used it to identify elements.

2$



Ma Planc4 ( K&K ,>0/ /xplained certain aspects of blackbody radiation/ >lackbody any ob ect that is a perfect emitter and a perfect absorber of radiation

/ 2un and earthBs surface behave approximately as blackbodies/ $roposed that energy4 like matter4 is discontinuous./ Chen the energy increases from one allowed value to the next4 it increases by a tiny ump

or 0uantum.

/ 3atter could absorb or emit energy only in the whole number multiples of the 0uantity./ O h v where / is energyh is $lanckBs constant O +.+"+ x 1;?% Gs; is fre0uency

2o4 T/ O n hv Chere n is an integer (14"4%Q!

• /nergy is J0uantized and can only occur in discrete units of size hv (packets of energycalled uantum!

• )ransfer of energy can only occur in whole 0uanta4 thus4 energy seems to have particulateproperties.

+lbert 'insetein ( K0, ,&&/ $roposed that electromagnetic radiation is itself 0uantized/ /lectromagnetic radiation can be viewed as a stream of particles called $9=)=H2

Summary of the 5or4s of 'instein and Planc4s/ /nergy is 0uantized. It can occur only in discrete units called 0uanta./ /lectromagnetic radiation4 which was previously thought to exhibit only wave properties4

also exhibit particulate properties4 thus the dual nature of light.

If light has particulate properties not just wave does matter also have wave properties not just particulate1

Louis de @ro"lie ( K,- ,K0/ 2mall particles of matter may at times display wavelike properties./ &or a particle with velocity4 vm O h R v

)hen R O h mv)hus4 we can calculate the wavelength for a particle.

/ All matter exhibits both particulate and wave properties./ 7arge pieces of matter predominantly exhibit particulate properties because their R is so

small that it is not observable./ Eery small pieces of matter such as photons exhibit predominantly wave properties./ )hose with intermediate mass4 such as electrons4 show clearly both particulate and wave

properties.

M9D'3N HB'5 9= T.' +T9M

A77=)8=$/ elements with different forms (composed of one type of element!I2=)=$/2 elements with different mass number due to the difference in the number of neutronsI2=>A82 different elements with the same mass number but different atomic number

Atom and the subatomic particles)he diameter of an atom is in the order of 1;?D cm)he nucleus is roughly 1;?1% cm in diameter (1 1;;4;;; diameter of the atom!)he charge of the nucleus is a uni0ue character of the atoms of an element)he charge is positive

2%



$articles within the nucleusP39T9N

/ugene #oldstein (1DD+! from #reek Jprotos meaning Jfirst mass of pL O 1.+@ x 1;?" g charge O L1.+; x 1;?1< c)he no. of pL is a uni0ue property of an element

U of pL O atomic U4 NO nuclear chargeO U of e?s in a neutral atom

N'UT39NGames -hadwick (1<%"!$rotons cannot account for the total mass of the atom9as the same mass as the proton but has no charge2ymbol6 n;mass of ) $ $ mass of n % # mass of atom (atomic mass of ) $ $ of n % # mass < + + # G $ of n %

'L'7T39N/rnest 8utherfordnegatively chargedin a neutral atom 6

U of e? O U of pL O N

Summary:Particle Disco;ery Mass in "rams 7har"e/lectron discovered by GG )homsonF name given by #eorge

2toney<.11 x 1;?"D ?1

$roton discovered by 8utherford in 1<114 name given by

#oldstein

1.+@ x 1;?" L1

Heutron discovered and named by Games -hadwick4 1<%" 1.+@ x 1;?" ;

2ymbol of the Atom+tomic number 4 N4 is the number of protons in thenucleus/x. )he element H has @ protons4 so NO @.

Mass number 4 A4 is the sum of the number of protonsand neutrons in the nucleus of an atom/x. An atom with * protons and * neutrons has anatomic number of * and a mass number of 1;

I2=)=$/2&rancis Cilliam Astron (1D@@?1< *!

* observed using the mass spectrometer that neon has % isotopes)he listed atomic mass of an element is the weighted average of the atomic masses of thenaturally occurring isotopes.

Atomic mass OΣ ( abundance!(isotopic mass!

&or Ions(L! charge cation

? 7ost electrons e0ual to the charge(?! charge anion

? #ained electrons e0ual to the charge2,



H5-7/A8 -9/3I2)8P? proposed by 3arie -urie (1D+@?1<% !

2pontaneous disintegration of an unstable atomic nucleus with accompanying emission of radiationin order to form a more stable species.

Huclear /0uation

+ )he sum of the mass UBs (A! must be the same on both sides+ )he sum of atomic UBs (N! must be the same on both sidesHuclide

+ A nucleus with a specified mass U (A!4 U of pL (N! and U of n;

+ 2table nuclide+ 8adioactive nuclide

Stability of Nuclide+ 9DD 'H'N 3UL'

+ /ven U of n; and pL 6 more likely to be stable+ =dd U of n; and pL 6 more likely to be unstable

+ M+8B7 NUM@'3+ Isotopes with specific U of pL or n; are more stable than the rest6+

"4 D4 ";4 "D4 *;4 D" and 1"++ All nuclides with D or more protons are radioactive.+ e. g. $o4 At Q.

)P$/2 =& 8A,I=A-)IE/ ,/-AP 1. A7$9A ,/-AP =8 /3I22I=H

+ α? particle6+ 9eavy4 travel short distances+ 5sually emitted by a heavy

nuclei

". >/)A ,/-AP =8 /3I22I=H =8 H/#A)8=H /3I22I=H+ β particle (negatron!

+ 5sually when neutrons are inexcess4 they are transformed intoprotons with emission of betaparticles.

%. $=2I)8=H /3I22I=H+ 5sually when pL are

in excess4 these are transformed inton; with emission of positron

. /7/-)8=H -A$)58/ =8 K? -A$)58/+ 5sually happens when pL are in

excess (as in positron emission!+ Huclear stability achieved by capturing

one of the inner e?s (lowest / level or K? shell! converting a pL to a n;

+ V?rays emitted*. #A33A /3I22I=H ( γ radiation is emitted!

+ high energy photons or radiation similar to x?rays but shorterλ 4 high ν4 highpenetration

+ no mass4 A and N of nucleus remainunchanged

28



H5-7/A8 &I22I=H+ 9eavy nucleus splits into " or more lighter nuclei+ =ccurs when a heavy nucleus is struck with pro ectiles or bullets (nuclear particles!

H5-7/A8 &52I=H+ Huclei of lighter elements are made to combine to form heavier nuclei+ =ccurs at very high temp.+ 3ore / released but difficult to harness

9A7&?7I&/4 t1 "+ )ime re0uired for half of radioactive nuclei in a sample to undergo radioactive decay+ -onstant for every radioactive isotope

t1 " O ln " k k is the rate

ln (H H; ! O ?kt H; O initial amount or activityH O amount left or activity left after time t

T.' 'LUSBH' 'L'7T39N

uantum Humber describes the orbital and the electron=8>I)A7 is an energy state for an electron described by the three 0uantum numbers n4 l and ml

? may hold two electrons with opposite spins

1. $rincipal uantum Humber (n!)ake positive4 nonzero integral values6 14"4%Q3ain energy level or principal shell As n increases6

orbital becomes larger4 e? becomes farther from the nucleushigher /? e? is less tightly bound to the nucleus

". Azimuthal or Angular 3omentum uantum Humber (l!Ealues6 ; to n?1 for each value of n2ublevel or subshell8elated to the shape of the orbital

=rbital 2ymbol? combination of n and l? consists of a number (for n! and a letter (for l!

e.g. %s n O % F l is s O ;

%. 3agnetic uantum Humber (ml!Ealues6 l to l including zero8elated to the orientation in space of the angular momentumassociated with the orbital

,egenerate orbitals orbitals having the same energies29

l !etterdesignation

, s% p' d

f



e.g. the three p?orbitals have the same energy

. /lectron 2pin uantum Humber (ms!Ealues6 L1 "4 ?1 ")he value does not depend on any of the three0uantum numbers

Pauli ' clusion Princi)le (5olf"an" Pauli ,%%,&K? In a given atom4 no " e?Bs can have the same set of 0.nos.

)hus4 an orbital can hold only " e?Bs4 and they must have opposite spins.

/lectronic -onfiguration describes the manner in whichelectrons are arranged in an atom

#round state electronic configuration? lowestenergy arrangement of electrons

/xcited state? allowed arrangements of electronsother than the ground state

Isoelectronic? same number of electrons

8ules to remember when writing ground state electronicconfigurations

- +ufbau Princi)le ? the orbitals of an atom are filled in order of increasing energy. According to the (nLl! rule. )he lower the value of (nLl!4 the lower the energy of

the orbital. If the (nLl! values of two orbitals are the same4 the one with lower n isfilled first.

- .und s 3ule of Multi)licity ? the lowest energy arrangement of electrons in a set of degenerate orbitals is where there is a maximum number of electrons of the same spin./lectrons occupy degenerate orbitals singly before pairing.

T.' P'3B9DB7 T+@L'

)he /lements• there are 11" elements to date4 <; of which

are naturally occurring

/arly -lassifications1. Gohann Colfgang ,obereinerBs 7aw of )riads(1D1@!? In a triad 4 the combining weight of the centralmember is the average of its partners.

". Gohn HewlandsB 7aw of =ctaves (1D+*!? Chen elements are arranged in increasing atomic mass4 every eighth element had similar properties.2hortcomings6

2ome positions were forced ust to maintain his proposition2ome positions contained " elements)here were no room for other elements which may be discovered

%. Gulius 7othar 3eyerBs Atomic Eolume -urve and $eriodic )able (1D+<! A periodic trend in properties is observed when elements are arranged in increasing atomicweights.

. ,mitri 3endeleevBs $eriodic )able and $eriodic 7aw (1D+<!$roperties of elements are periodic functions of their atomic weights

30



$redicted the discovery of 1; elements

)he 3odern $eriodic 7aw? )he properties of the elements are functions of their atomic numbers

#roupsEertical rows$revious notation6 IA EIIIA4 I> EIII

Hew I5$A-' notation6 1?1D'I5$A- International 5nion of $ure and Applied -hemistry

/lements belonging to the same group have similar (not identical! properties2pecial names of some groups

#roup 1 Alkali metals#roup " Alkaline earth metals#roup 1@ 9alogens#roup 1D Hoble #ases

$eriods9orizontal rows$roperties of elements that belong to a period show a pattern or trend that is repeated inthe next periodHumbered 1?@

$attern in Ion &ormation3ost elements form ions (except noble gases!

#roup 1 6 L1 #roup 1* 6 ?%#roup " 6 L" #roup 1+ 6 ?"#roup 1% 6 L% #roup 1@ 6 ?1#roup 1 6 do not readily form ions

=f the known elements4 11are gases at room temperature. four are li0uids at "*W-4 9g4 >r4 #a and-s. If &r can be prepared in large 0uantities4 it is expected to be a li0uid.

Pro)erty +cross a )eriod (left to ri"ht Down a "rou) (to) to bottom

atomic size radius ,ecreasing Increasingionization energy Increasing ,ecreasingaffinity for electrons Increasing (upto #roup 1@! ,ecreasing)endency to form-ation

,ecreasing Increasing

)endency to form Anion

Increasing (upto #roup 1@! ,ecreasing

3etallic -haracter ,ecreasing Increasing/lectronegativity Increasing ,ecreasing

Hote6 )he size of the cation is smaller as compared to its neutral atom)he size of the anion is larger as compared to its neutral atom.

Atomic 2izeX -ovalent radius Y the distance between the nuclei of two identical atoms oined by asingle covalent bond.

X 3etallic radius Y the distance between the nuclei of " atoms in contact in the crystallinesolid metal.

Ionization /nergyX /nergy re0uired to remove an e? from a gaseous atom or ion

V(g! → VL(g! L e?

Chere the atom or ion is assumed to be in its ground state

Affinity for electrons31



X )endency of an atom or ion to attract additional e?V(g! L e?→ V?

(g!

/lectronegativityX )he attraction of an atom for shared electrons.

Hote63etals react with oxygen gas forming a basic oxide in water.Honmetals react with oxygen gas forming an acidic oxide in water.

7.'MB7+L L+N8U+8' +ND S.93T.+ND-hemical symbols

An element is represented by a symbol which may be one or two lettersF the first iscapitalized and the second is in the lower case. )he symbols may be derived from the #reek4#erman or 7atin names of the elements.

@inary 7o;alent 7om)ounds >inary covalent compounds are formed between two non?metals

+! Namin" binary co;alent com)ounds1. Identify the elements present in the compound given by the chemical formula. )he name of themore metallic element is written first.

". -hange the suffix of the less metallic element to ide.%. 5se the prefix corresponding to the number of atoms present in the compound.

Humber #reek $refix Humber #reek $refix1 3ono? + 9exa?" ,i? @ 9epta?% )ri? D =cta?

)etra? < Hona?* $enta 1; ,eca?

)he mono? prefix is fre0uently omitted4 particularly for well?known substances. If no prefix is use4usually implies that no number of atoms of element is one. 9owever4 experts in nomenclaturecaution that this can be dangerous and suggest that it is better to include the mono? prefix.

2ome compounds are known only by their common names. )he most common of this are6=orrmula

9 "=H9%$9 %

NameCater Ammonia$hosphate

! 5ritin" formulas of binary com)ounds

1. 8epresent each kind of element in a compound with the correct symbol of element.". Indicate by a subscript the number of atoms of each element in a molecule of the compound.%. Crite the symbol of the more metallic element first. (9 is an exception to this rule.!

B9NB7 79MP9UNDS-ompounds formed between metals and nonmetals are called ionic compounds.

+! Namin" Bonic 7om)ound1. Crite the name of the cation first4 followed by the name of the anion.". 5nlike binary covalent compounds4 $8/&IV/2 A8/ H=) 52/ to indicate the number of

ions present in the formula.

32



Hote that for ionic compounds4 the prefixes are not attached to the chemical name to denotethe number of atoms of the elements. )he number of atoms is implied by the charges of thecation and the anion. It is therefore important to know the charges of the common cations andanions.

%. 3ost transition metals can exist in more than one ionic form. )hus4 it is important to know thecharge of the cations in their compounds.

/xamples6 &ormula 2tock system =ld system2n-l tin (IE! chloride stannic chloride2n>r " tin (II! bromide stannous bromide

)he method of indicating the charge of the cation involves placing a 8oman numeral e0uivalentto the magnitude of the charge of the cation in parenthesis after the /nglish name is called the2tock 2ystem of Homenclature.

2ome ionic compounds form crystals that contain a certain proportion of water molecules apartfrom the ions of the compound. 2uch compounds are called 9P,8A)/2. 9ydrates are named ust like other ionic compounds except for the addition of the Jhydrate with a #reek prefiindicating the number of water molecules per unit of the ionic compound./xample6 -u2= •*9"= copper (II! sulfate pentahydrate or cupric sulfate pentahydrate

@! 5ritin" =ormulas of Bonic 7om)ounds1. Crite the symbol of the positive ion (cation! first4 followed by the symbol of the negative io(anion!.

". Crite the charge of each ion over the symbol of that ion. 5sually4 for the main groupelements4 the group number usually gives the charge of the monoatomic ion. 8emember that#roup 1 elements would have a charge of (L1!F #roup " (L"!F #roup % (L%!F #roup 1+ (?"!#roup 1@ (?1!F and #roup 1D (;! unless indicated.

%. -hoose a subscript that will make the net charge zero. )he simplest procedure is to use theabsolute value of the charge of the anion as the subscript for the cationF and the absolute valueof the cation charge as the subscript for the anion (-8=22?=E/8 857/!. Chen bothsubscripts in the formula can be divided by same number to simplify the formula4 you should doso4 unless you know the actual molecule represented.

. &or hydrates4 follow the same steps4 then add a centered dot4 followed by the number owater molecules (indicated by the prefix! and the chemical formula of water.

+7BDS+! Namin" @inary +cids

>inary acids contain only two different elements? hydrogen and a nonmetal. >inary acidsare named ashydro 2222ic acid 4 where the stem of the nonmetal is inserted in place of the line.)hus4

9&? hydrofluoric acid and 9>r? hydrobromic acid

)he names hydrogen fluoride and hydrogen bromide are also used for 9& and 9>r4respectively. >oth names are correct although the convention is that these compounds are namedas acids when they are present in a0ueous solutions. )hus4 9& in a0ueous solution is hydrofluoricacid4 but pure 9& is referred to as hydrogen fluoride.

@! Namin" 9 yacids Another type of acid is the oxyacids derived from the oxyanions. 2ince some elements

form more than one oxyanion4 they also form more than one oxyacid. )he name of the oxyacid isderived from the name of the oxyanion with a change in the suffix using the following rules6

1. If the name of the oxyanion ends in ate4 the name of the oxyacid will be of the form 2222ic acid .

33



/xample 2= "? sulfate 9"2= sulfuric acid-l= ? perchlorate 9-l= perchloric acid

". If the name of the oxyanion ends in ite4 the name of the oxyacid will be of the form ZZZ ousacid .

/xample 2=%"? sulfite 9"2= % sulfurous acid

-l= ? hypochlorite 9-l= hypochlorous acid

Hames and 2ymbols of 2ome -ommon $olyatomic Anions&ormula Hame &ormula Hame=9 ? 9ydroxide H=%? Hitrate= "

"? $eroxide H="? Hitrite

-H ? -yanide -9 %-== ? AcetateH%

? Azide -r= "? -hromate2= "? 2ulfate -r "=@

"? ,ichromate2= %

"? 2ulfite 3n= ? $ermanganate92= ? 9ydrogen sulfate or

bisulfate- "= "? =xalate

92= %? 9ydrogen sulfite or

bisulfite2-H ? )hiocyanate

$= %? $hosphate -= %"? -arbonate

9$= "? 9ydrogen phosphate 9-=%? 9ydrogen carbonate or

bicarbonate9 "$= ? ,ihydrogen phosphate2ome common oxyanions

-hlorine >romine-l= ? $erchlorate >r=? $erbromate-l= %

? -hlorate >r=%? >romate

-l= "? -hlorite >r="

? >romite

-l=?

9ypochlorite >r=?

9ypobromiteST9B7.B9M'T3I-hemical 8eactions

/ $rocesses in which substances are changed into one or more new substances/ 8epresented by chemical e0uations6

8eactants $roducts

"9 " L 1 =" "9 "=" molecules L 1 molecule " molecules" moles L 1 mole " moles

34



.; g L %".;; g %+.; g

%+.; g reactants %+.; g products&=77=C2 )9/ 7AC =& -=H2/8EA)I=H =& 3A22

>alancing -hemical /0uations2ome important points6

/ 5se correct chemical formulas/ Ad ust only the coefficients4 H=) the subscripts/ >alance elemental forms ( e.g. Ar4 -u4 Ha4 ="4 H"4 I"4 2DQ! and 9 and = last./ 5se the simplest possible set of whole no. coefficients

2toichiometry? )he 0uantitative study of reactants and products in a chemical reaction3ole 3ethod ? )he stoichiometric coefficients in a chemical e0uation can be interpreted as thenumber of moles of each substance.

2teps6/ Crite correct chemical formulas and balance the e0uation./ -onvert the 0uantities into moles./ 5se the mole ratios to calculate moles of the re0uired substance./ -onvert calculated moles to whatever units re0uired.

)hree types of calculation6

he MoleIn 1<@14 at the 1th meeting of the #eneral -onference of Ceights and 3easures4 scientists agreedto adopt themole as the unit of an amount of substance

)he mole (abbreviated mol! is the amount of substance that contains the same number of elementary particles as the number of atoms in exactly 1" grams of -?1".

Cays of expressing the mole61. by number of particles (use AvogradoBs number4 +.;" x 1;"% particles per mole!". by mass (use molar mass!%. by volume (use molar volume4 "". 7 at 2)$!

Interconversions

3ass 3ole Ho. of particles

3$

MM

x MM

x 0&,' x %, '

0&,' x %, '



)he molar mass is the mass in grams of 1 mole of a substance. )he molar mass is numericallye0ual to the atomic mass (or atomic weight! of an atom or the formula mass of a molecule4 acompound or a polyatomic ion.

=ormula and 7om)osition)he percentage composition of a compound is a list of the percentages by weight of the elementsin the compound. )he percentage by weight of an element in a compound is numerically e0ual to

the number of grams of the element that are present in 1;; g of the compound/x. Chat is the percentage composition of 0uick lime4 -a=: Ans. @1.* -a4 "D.* =

'm)irical =ormula ? is the formula with lowest possible whole number subscripts to represent thecomposition of the compound. It can be determined from the composition data.

/x. >arium carbonate4 a white powder used in paints4 enamels and ceramic4 has the followingcomposition6 >a4 +<.*D F -4 +.;<; and =4 " .;% . ,etermine its empirical formula

Ans. >a-= %

Molecular =ormula ? gives the actual composition or the actual number of atoms of each elementpresent in one molecule or one formula unit of the compound

/x. 3olecular formula of glucose6 -+9 1"=+ /mpirical &ormula of glucose6 -9"=

Stoichiometry of 3eactions7hemical Stoichiometry ? is the 0uantitative relationship of the amounts of reactants used andamounts of products formed in a reaction. )his mass relationship is expressed in the balancede0uation for the reaction.

Percent yield ? portion of the theoretical yield of product that is actually obtained in the reaction

yieldO (actual amt of product obtained theoretical amt! x 1;;

)heoretical Pield ? the amount of product that would result if all the 78 reacted.? 3aximum obtainable yield

Actual Pield ? )he amount of product actually obtained from a reaction? Always less than theoretical yield

Limitin" reactant ? reactant that is completely consumed in the reaction. It also determines theamount of products that can be formed.

' cess reactant ? reactant that is not completely used up in a chemical reaction

TB'S T.+T 7.'MBST3I @BND

7hemical @onds net forces of attractions that hold atoms together $roperties6>ond energy amount of energy that must be supplied to separate the atoms that make abond>ond length distance between " nuclei of " covalently bonded atoms>ond order number of bonds between atoms

)ypes of -hemical >ondsa. co;alent bond ? pair of electrons that is shared by two atoms of nonmetalsF represented by7ewis structure or electron dot formula

3%



)ypes of -ovalent >onds62ingle bond ? two atoms held by one e? pair ,ouble bond two atoms held by " e? pairs)riple bond two atoms held by % e? pairs

/ .i"her @ond order< shorter @ond len"th< hi"her @ond ener"y

$olar covalent bond one atom is more electronegative than the other atomF une0ual

sharing of electronsF the more electronegative atom is partially negative and the lesselectronegative atom is partially positive.

Honpolar covalent bond e0ual sharing of electrons

-oordinate -ovalent >ond the electrons being shared comes from a single atom

b. ionic bond or electro;alent bond It is the transefer of electrons from a metal to a nonmetal4i.e.4 the metal loses an electron while the nonmetal gains an electron converting them intro chargedions.

? attraction between cations and anions

c. metallic bond ? the attraction between the cations in the lattice and the Jsea of delocalizedelectrons moving within the lattice

Lewis Structure ?one or a combination of 7ewis symbols to represent a single atom (neutral or charged!4 a molecule or a polyatomic ion.

? based on =ctet 8ule

=ctet rule? the observed tendency of atoms of the main block elements to lose4 gain or shareelectrons in order to ac0uire an octet of electrons in their outermost main energy level It is moreappropriately called Hoble #as 8ule

/lectron $airs could either be7one pairs pairs of electrons localized on an atom>onding pairs those found in the space between the atoms

,rawing 7ewis 2tructures1. 2um the valence electrons from all atoms (total U of e?Bs!

)otal electrons O sum of the valence electrons of all atoms charge". ,etermine the central atom and draw the skeletal structure.

-ental atom is the most metallic atom or the least electronegative.%. 5se a pair of e?Bs to form a bond between each pair of bound atoms.

. ,istribute remaining electrons to the terminal atoms to satisfy octet.*. If there are still available electrons4 put them on the central atom to satisfy octet.+. If the central atom does not satisfy octet4 move electron pair (lone pair! from the terminal atomtowards the central atom to form multiple bonds.

2)8I-) &=77=C/82 of =-)/)6 -4 H4 =4 & and 9 (" electrons!@. -heck the 7ewis structure. 9 and & are always terminal atoms and oined by a single bond.9P$/8EA7/H) A)=3 atom that could accommodate more than the octet due to low?lying d?orbitals.

8/2=HAH-/ ? )he use of two or more 7ewis 2tructures to represent a particular molecule or ion.? -an be written for molecules ions having a double or a triple bond and single bond(s!.

8esonance 2tructures one of two or more 7ewis structures for a single molecule that cannotbe represented accurately by only one 7ewis structure.? )he true structure is the average or the Jhybrid of the resonance structures.

&=83A7 -9A8#/? 5sed to evaluate non?e0uivalent 7ewis structures (different from resonancestructures!

O no. of valence electron in the free state no. of nonbonding electrons no. of bonds

3,



8'9M'T3I 93 S.+P' 9= M9L'7UL'S? the three?dimensional arrangements of atoms in a molecule? governed by E2/$8 )heory

Ealence 2hell /lectron $air 8epulsion (E2/$8! )heory? )he structure around a given atom is determined principally by minimizing electron pair repulsions

2teps for using E2/$8 )heory1. ,raw the 7ewis structure for the molecule ion.2. -ount the e? pairs around the central atom and arrange them in the way that minimizes

repulsions.3. ,etermine the positions of the atoms from the ways the e? pairs are shared.4. Hame the molecule structure from the positions of the atoms.

Ty)e of Molecule 8eometry Polarity AV" 7inear Honpolar AV% )rigonal planar Honpolar AV"/ >ent or E?shaped $olar AV )etrahedral Honpolar AV%/ )rigonal pyramidal $olar AV"/ " >ent or E?shaped $olar AV* )rigonal bipyramidal Honpolar AV/ 2ee?saw shaped $olar AV%/ " )?shaped $olar AV"/ % 7inear Honpolar AV+ =ctahedral Honpolar AV*/ 20uare pyramidal $olar AV/ " 20uare planar Honpolar AV%/ % )?shaped $olar AV"/ 7inear Honpolar

' )he polarity are always )85/ if the substituents are the same since the net dipole is zero. )hedipole moments cancel out.

V number of substituents / no. of lone pairs8epulsion =rder67one $air (7$! 7$ repulsion [ 7$? bonding pair (>$! repulsion [ >$? >$ repulsion

'&or the E2/$8 model 4 molecules with multiple bonds4 multiple bonds count as one effective e?pair ' Chen a molecule exhibits resonance4 any one of the resonance structures can be used to predictthe geometry

38



>ond $olarity results from a net dipole moment,ipole moment results from the

difference of electronegativity

BNT'3M9L'7UL+3 =937'S 9=+TT3+7TB9N (BM=+

Interactions among molecules (not within

the molecules!Ceaker than ionic or covalent bonding/xplains the physical states of themolecules

)ypes61. 7ondon ,ispersion &orces (7,&!". ,ipole?,ipole &orces (,,&!%. 9ydrogen >onding

London Dis)ersion =orces (LD=8elatively weak forces that exist among noble gas atoms andnon?polar molecules Atoms can develop a momentary non?symmetrical e?

distribution (instantaneous dipole!)his atom can induce a similar dipole in the neighboring atom$olarizability

)he ease with which a dipole can be induced in an atom or moleculeIncreases with increasing no. of e?Bs (increased 33!. resultsto higher boiling pointIncreasing polarizability4 stronger 7,&

Di)ole di)ole =orces/xhibited by polar molecules2tronger than 7,&=nly about 1 as strong as covalent or ionic bonds3olecules with dipole moments can attract each other electrostatically so that the positiveand negative ends are close to each other

.ydro"en @ondin"2pecial type of dipole?dipole forces/xhibited by molecules with 9?&4 9?= or 9?H bonds=ccurs when an 9 atom is Jsandwiched between&4= or H6

2trongest I3&A due to62mall size of the 9 atom molecules can approacheach other closely9igh electronegativity of &4=4H 9 is pulled closelyF highly polar bond

)he structure of ice due to 9?bonding is shown onthe left. )here is hollow space making ice lessdense than water.

Nature of LiCuids as 'ffects of BM=+ 1. 2urface )ension? Ability to resist an increase in surface

area2tronger I3&A4 higher surface tension

".Eiscosity fluidBs resistance to flow

39





At constant temperature4 phasechange occurs and at thistemperature4 kinetic energy isconstant while potential energy isincreasing

At increasing temperature4 kinetic

energy is increasing while potentialenergy is constant.

P.+S' DB+83+M

)riple point all %states are present

-ritical point6-ritical temp. temp.abovewhich the vapor cannot beli0uefied nomatter whatpressure isapplied-riticalpressure pressure

re0uired to produce li0uefaction at the critical temp.

2upercritical &luid (2-&!9as the high density of a li0uid but the low viscosity of a gas3olecules in 2-&4 being in much closer proximity than in ordinary gases4 can exert strongattractive forces on the molecules of a li0uid or solid solute

8+S'S$roperties6

/xpansionIndefinite shape-ompressibility/ase of mixing

7ow densityGan >aptista van 9elmont? coined the term Jchaos or Jgas

/vangelista )oricelli? showed that the air in the atmosphere exerts pressureF designed the firstbarometer

$roperties of #ases (3easurable!1. $ressure ($!? force per unit area

$O & A 2I unit6 1 $aO 1 H m"

2tandard atmosphere 6 1 atmO@+; mm9gO@+; torrO1;1%"* $a O 1.;1%"* bar

41



". Eolume (E!? space occupied by the gas (unit6 74 m7!1 dm% O 17F 1 cm% O 1 m7

%. )emperature ()!? expressed in K4 W- or W&KO W- L "@%.1*

Absolute zero tempO ; KO ?"@%.1*W- molecules stop moving2tandard )emperature and $ressure (2)$!6 ;W-4 1 atm

2tandard Ambient )emperature and $ressure (2A)$!6 "*W-4 I bar . no. of moles of gas (n!

#as 7aws

1. >oyleBs 7aw? 8obert >oyle? the volume occupied by a given mass of gas at const temp is inversely proportional to thepressure (E ] 1 $!

• does not apply to li0uids and solids• applies only at moderate or low $ and moderate or high )

$1E1 O $"E"

". -harleBs 7aw? Gac0ues -harles (1@ +?1D"%!? the volume occupied by a given mass of gas at const pressure is directly proportional to temp (E] )!

-harles is the first person to fill a balloon with hydrogen gas (3ade the first solo balloonflight!E1 O E") 1 ) "

%. AvogadroBs 7aw? Amadeo Avogadro (1@@+?1D*+!? for a gas at const ) and $4 E is directly related to the no. of moles of gas (E ] n!3olar volume? one mole of any gas at 2)$ occupies a volume of "". 7

E1 O E"

n1 n"

. #ay?7ussacBs law? the pressure occupied by a given mass of gas at const volume is directlyproportional to temp ($ ] )!

$1 O $") 1 ) "

*. -ombined gas law($E! ) O k4 hence ($1E1! )1 O ($"E"! )"

+. Ideal #as 7aw$EO n8)Chere $ O $ressure (atm!

E O Eolume (7!n O no. of moles (mol!

8 O 5niversal gas constantO ;.;D"1 7?atm mol?K ) O )emperature (K!

,altonsBs 7aw of $artial $ressures&or a mixture of gases in a container4 the total pressure exerted is the sum of thepressures that each gas would exert if it were alone.

$total O $1 L $" L $% L Q L $nChere $14 $" and $% are partial pressures of the gas each gas would exert if it were alonein the container.

42



#rahamBs 7aw of /ffusion ? )homas #raham (1D;*?1D+<!J )he rates of effusion of " different gases are inversely proportional to the s0uare roots of their molar masses.

/ffusion ?/scape of gas particles from their container through a tiny orifice or pinhole.

&or " gases A and >6

8ate of effusion of A O ^33>8ate of effusion of > ^33 A

S9LUTB9NS?homogeneous solutions-omponents6

+ 2=75)/ substance being dissolvedF present in smaller amount+ 2=7E/H) the dissolving mediumF present in larger amount

2olubility ? )he maximum amount of solute that can be dissolved in a given amount of solvent at agiven temperature

)ypes of 2olutions6+ ,I75)/ 2=75)I=H relatively little solute present+ -=H-/H)8A)/, 2=75)I=H relatively large amount of solute present

)ypes of 2olutions based on amount of solute dissolved6

/ 5H2A)58A)/, contains less than the maximum amount of solute that can be dissolved/ 2A)58A)/, contains the maximum amount of solute that can be dissolved/ 25$/82A)58A)/, contains greater than the maximum amount of solute that can be

dissolved

-oncentration? )he amount of solute present in a given 0uantity of solvent or solution

Cays of /xpressing 2olution -oncentration1. 3olarity4 3 O moles of solute 7 of solution". 3ass $ercent or Ceight $ercent O (g solute g solution! x 1;;

%. 3ole &raction4 V O moles of a component moles of solutionO moles solute (moles of solute L moles of solvent!

. 3olality4 m O moles solute kg solvent

&A-)=82 A&&/-)IH# 2=75>I7I)P1. 2tructure effects

J7ike dissolves likeIn general4 substances that have similar I3&A have strong solute?solvent interactions and

tend to form solutions.

". $ressure+ Affects solutions containing gases+ 9igher pressure4 higher solubility of a gas in li0uid

%. )emperature&or solid solute and li0uid solvent6+ &or an endothermic dissolution6 higher temperature4 higher solubility+ &or an exothermic dissolution6 higher temperature4 lower solubility

&or gas solute and li0uid solvent6+ Increasing temperature4 lower solubility

43



2toichiometry in solutions6• 8elate mole of reactant to mole of another reactant• 8elate mole of reactant to mole of product• 8elate mole of product to mole of another product

makes use of balanced chemical e0uation always convert to mole since the balanced e0uation is in terms of mole.

,I75)I=H procedure for preparing a less concentrated solution from a more concentrated one.3 1E1 O 3"E" where 3 molarity and E? volume

79LLB8+TBH' P39P'3TB'S? 2olution properties that depend on the amount of solute present and not on the nature of thesolute

1. Eapor $ressure 7owering? )he presence of a non?volatile solute lowers the vapor pressure of a solvent

". >oiling $oint /7evation? )he presence of a non?volatile solute increases the boiling point of a solution

>$solution >$solvent O Kb m where Kb is the boiling point elevation constantm is the molality

%. &reezing $oint ,epression? )he presence of a non?volatile solute decreases the freezing point of a solution

&$solvent &$solution O Kf m where Kf is the freezing point depression constantm is the molality

. =smotic $ressure? $ressure re0uired to stop osmosis

=smosis ? selective passage of solvent molecules through a porous membrane from adilute solution to a more concentrated one

2emi?permeable membrane ? ? Allows the passage of solvent molecules but blocks thepassage of solute molecules

_ O 38) Chere _ O osmotic pressure3 O molarity of solution8 O gas constant) O Kelvin temp.

+7BDS +ND @+S'S

Arrhenius ,efinition (2vante Arrhenius4 1D*<?1<"@! Acid ? substance that when dissolved in water4 increases `9L

>ase ? substance that when dissolved in water4 increases `=9?

>ronsted?7owry ,efinition (G.H. >ronsted and ).3. 7owry4 1<"%! Acid a proton donor >ase ? a proton acceptor

-on ugate base product formed when an acid loses a proton-on ugate acid? product formed when a base accepts a proton

3onoprotic acid donates 1 mole 9L per mole of acid$olyprotic acid donates more than 1 mole 9L per mole of acid Amphiprotic ? 2ubstance that can act either as a proton donor or proton acceptor

Kw O `9%=L `=9? O 1.; x 1;?1

44



p9 O ?log `9%=L

p=9 O ?log `=9?p9 L p=9 O 1

2trong Acids9-l 9>r 9I 9-l=9H=% 9 "2= (1st ionization only!

2trong >ases9ydroxides of #roups 1 and "

Ceak Acids and >ases ionizes to small extent)he larger the Ka (ionization constant of acid!4 the stronger the acid4 greater `9%=L

)he larger the Kb (ionization constant of base!4 the stronger the base4 greater `=9?

7ewis ,efinition (#ilbert Hewton 7ewis4 1D@*?1< +!>ase a substance that can donate an e? pair Acid a substance that can accept an e? pair

)itration. a neutralization reaction. a solution is gradually added to another solution until the solute of the first solution hascompletely reacted with the solute of the second solution

Indicator an organic compound that changes color depending on the p9e.g. phenolphthalein colorless acidic

faint pink neutralpink basic

/0uivalence $oint? the point at which the solute of the first solution has completely reacted with thesolute of the other solution

/ndpoint approximates the e0uivalence point. It is very close to the e0uivalence point.

2tandardization it is the process of determining the concentration of a solution using a standardsolution. )he solution has a known concentration.

)itrant? the solution usually placed on the buret. )his is usually the solution of known concentration.

Analyte? the solution of unknown concentration usually placed in the /rlenmeyer flask.

@U=='3S? A solution that resists drastic changes in p9 when small amounts of acids or bases are added.

-omponents6 A weak acid and its con ugate base (in salt form!93 A weak base and its con ugate acid (in salt form!

pKa O ? log KapKb O ? log Kb

9enderson?9asselbach e0uation6 p9 O pKa L log ̀ base `acid7.'MB7+L 'QUBLB@3BUM? )he state in which the forward and backward reactions continue to occur but the concentrations of all reactants and products remain constant with time.

-haracteristics61. Dynamic Situation 6 the forward and backward reactions continue to exist2. @alance the rate of forward reaction is e0ual to the rate of backward reaction

4$



3. Law of Mass +ction 6 reactions in e0uilibrium can be expressed in a ,efinite3athematical /xpression

&or a general e0uation6

aA L b> c- L d,

Ke0 O `-c `, d `Aa`> b where Ke0 is the e0uilibrium constant` molar concentration

In the expression4 only a0ueous and gaseous substances are included. 2olids and li0uids are notincluded since their concentrations are relatively constant.

Ke0 O Kc Kc is the e0uilibrium constant when substances are expressed in molar concentrationKp O Kc (8)!∆ng Kp is the e0uilibrium constant when substances are expressed in their

partial pressures8 is the universal gas constant and ) is the temperature in -elsius∆ng is the difference between the number of moles of gaseous particles of products and reactants

Ke0 [ 14 at e0uilibrium4 reaction system consist mostly of products?shift to the right? very large Ke06 reaction goes to completion

Ke0 14 at e0uilibrium4 reaction system consist mostly of reactants?shift to the left? reaction does not occur to a significant extent

7e -hatelerBs $rinciple ?9enry 7ouis 7e -hatelier (1D*;?1<%+!? If a change in conditions (a Jstress ! is imposed on a system at e0uilibrium4 the e0uilibriumposition will shift in a direction that tends to reduce that change in conditions.&actors Affecting /0uilibria

1. -hange in concentration. If a reactant or product is added to a system at e0uilibrium4 the system will shiftaway from the added component.

. If a reactant or product is removed4 the system will shift toward the removedcomponent.

". -hange in pressure affects only system involving gases

)hree ways to change the pressure of gaseous systems at a given temperature6a. Add or remove a gaseous reactant or product at constant volume? same effect as change in

concentrationb. Add an inert gas (not involved in the reaction! at constant volume increase in total pressure

but has no effect on concentrations or partial pressures of the reactants or productsc. -hange the volume of the container when the volume of the container holding a gaseous

system is reduced4 the system responds by reducing its own volume. )his is done bydecreasing the total no. of gaseous molecules in a system

%. -hange in temperature! FeC ;alue chan"es with tem)erature

-! /nergy is treated as a reactant (endothermic! or product (exothermic!/! If energy (heat! is added4 the e0uilibrium will shift to the direction which consumes the

added energy

4%



. -atalyst. 2peeds up both the forward and backward reactions. /0uilibrium is achieved more rapidly but the e0uilibrium amounts are unchanged. )herefore4 has no effect on e0uilibria

7.'MB7+L FBN'TB7S)he area of chemistry concerned with the speeds or rates at which a chemical reactionoccurs

-ollision )heory? -hemical reactions occur as a result of collisions between reacting molecules.&or a reaction to procede4 reacting particles must collide effectively to enable outer shellelectrons to interact.

-ollisions to be effective4 must be with enough energy to overcome repulsive forcesbetween electrons surrounding the nuclei of atoms.

Activation /nergy (/a!)he threshold energy that must be overcome to produce a chemical reaction

)ransition 2tate or Activated -omplex

A temporary species formed by the reactant molecules as a result of the collision beforethey form the product.

&A-)=82 A&&/-)IH# 8/A-)I=H 8A)/21. -oncentration higher concentration4 higher reaction rateF more molecules4 more collisions

". )emperature? 9igher temperature4 more collisions with high energy4 higher reaction rate

%. -atalyst? A substance that increases the reaction rate without itself being consumed.? hastens the reaction by providing a path with lower activation energy thus less energy is needed

for a reaction to proceed. $ressure? affects gaseous systems? higher pressure4 more collisionsF higher reaction rate

T.'3M97.'MBST3I/ 2tudy of heat changes in chemical reactions/ )hermal energy transferred between " bodies that are at different temperatures/ 5nits6 1 calorie O .1D G

2ystem A specific part of the universe that is of interest2urrounding )he rest of the universe outside the system

/xothermic $rocess 6 O (?!? 9eat is transferred from the system to the surroundings

/ndothermic $rocess6 O (L!? 9eat is transferred from the surroundings to the system

7AC =& )9/83=,PHA3I-21. &irst 7aw of )hermodynamics ? /nergy can be converted from one form to another4 but cannotbe created nor destroyed.

". 2econd 7aw of )hermodynamics ? In any spontaneous process4 there is always an increase inthe entropy (disorder! of the universe

4,



? )he entropy of the universe is increasing

/ 2$=H)AH/=52 $8=-/22 occurs without outside intervention (given the rightconditions!

/ H=H?2$=H)AH/=52 $8=-/22 can occur as long as they receive some sort of outside assistance

/ ∆# ; (negative! 2$=H)AH/=52/ ∆# [ ; (positive! H=H? 2$=H)AH/=52/ ∆# O ; (zero! at e0uilibrium

∆# O∆9 ?)∆2

7+L93BM'T3I? 3easurement of heat changes

/ -A7=8I3/)/8 a closed container used to measure heat changes

2pecific 9eat -apacity (-p!/ )he amount of heat re0uired to raise the temperature of 1g of the substance by 1o-./ An intensive property

9eat -apacity (2!/ )he amount of heat re0uired to raise the temperature of a given 0uantity of a substance by

1o-/ An extensive property/ 2 O m -p where m O mass

Amount of 9eat4 O m-p∆) where m is mass and∆) is final temperature initial temperature

If is positive4 the process is endothermic.If is negative4 the process is exothermic.Hote6 sys O ? surr

9ABD+TB9N 6 3'DU7TB9N (3'D9A 3'+7TB9N? /lectron transfer reactions

9A7&? 8/A-)I=H2hows the electrons involved in a redox reaction

a. =xidation half?reaction9alf?reaction that involves loss of electrons8/,5-IH# A#/H) (8eductant! donates e?Bs

b. 8eduction half?reaction9alf?reaction that involves gain of electrons=VI,INIH# A#/H) (=xidant! accepts e?Bs

3nemonics67/=8A 7oss of /lectron4 =xidation4 8educing Agent#/8=A? #ain of /lectron4 8eduction4 =xidizing Agent,isproportionation 8eaction? same substance on the reactant side is oxidized and reduced

-omproportionation 8eaction? same substance on the product side is oxidized and reduced

=xidation 2tate

48



? A concept that provides a way to keep track of electrons in redox reaction according to certainrules.

3UL'S 79NH'NTB9NS =93 D'T'3MBN+TB9N 9= 9ABD+TB9N ST+T'S&undamental 8ules6

1. )he sum of the oxidation state for all atoms in the formula for an electrically neutralcompound isEero .". )he oxidation state for any element in the free or uncombined state isEero .

%. )he oxidation state for an ion is the same as its charge.2pecial -onvention1. In all hydrogen compounds4 the oxidation state for 9 is L1.

/xception6 in hydrides where 9 is 1". In all oxygen compounds4 the oxidation state for = is ".

/xception6 in peroxides where = is 1%. In all halides4 the oxidation state for the halogens is 1.

. In all sulfides4 the oxidation state for sulfur is ".*. In binary compounds4 the element with the greatest attraction for electrons is assigned anegative oxidation state e0ual to its charge in its ionic compound.

/lectrochemistry? Area of chemistry that deals with theinterconversion of electrical and chemicalenergy

/lectrochemical -ell Eoltaic -ell #alvanic -ell/ )he experimental apparatus for

generating electricity through the use of a spontaneous redox reaction.

Parts:

Anode/ /lectrode at which oxidation occurs/ Hegative (?! terminal/ /lectrons leave

-athode/ /lectrode at which reduction occurs/ $ositive (L! terminal/ /lectrons enters

Chat occurs:/ /lectrons flow from anode to cathode in the external circuit./ =xidation occurs at the anode4 anions flow toward the anode within the cell/ 8eduction occurs at the cathode4 cations flow toward the cathode within the cell

Anolyte where anode is immersed-athoyte? where cathode is immersed

2alt >ridge maintains the neutrality/xternal Cire? pathway for electron flowEoltmeter

/ 3easures the cell potential/ #ives positive readings in volts

-ell 8epresentation or ,iagram/ Anode 8educing species (oxidized form! oxidizing species (reduced form! cathode

49





Aromatic cyclic derivative Aliphatic open?chain

=xygen -ontaining1. Alcohol (8?=9!". /thers (8?=?8!%. -arboxylic Acids (8-==9!

. /sters (8-==8!*. Aldehydes (8-=9!+. Ketone (8-=8!=thers61. alkyl halides (8V! where V is either &4 -l4 >r4 I". amines (8H9"!%. amides (8-=H9"!

N9M'N7L+TU3' 9= +LF+N'S

Alkanes are named by the I5$A- (International 5nion of $ure and Applied -hemistry! system4which uses a systematic set of rules. 3any also have non?systematic common or trivial names thatare still in use.

-ommon Hames At a time when relatively few organic compounds were known4 it was customary to name newcompounds at the whim of their discoverers. 5rea was so named because it was isolated fromurine. 3orphine4 a painkiller4 was named after 3orpheus4 the #reek god of dreams. >arbituric acid4a tran0uilizer4 was named by its discoverer after his friend >arbara. )hese older names for organiccompounds are now calledcommon or tri;ial names F many of these names are still widely usedin the chemical literature and in commerce.

In the common nomenclature4 the total number of carbon atoms in an alkane4 regardless of theirarrangement4 determines the name. )he first three alkanes are methane4 ethane and propane.&or alkanes beyond propane4 certain prefixes are used to differentiate the different structuralisomers.

)he prefixnormal or n is used to indicate that all carbons are oined in a continuouschain.)he prefix iso is used to indicate that one end of an otherwise continuous chainterminates in a (-9%!"-9? group)he prefix neo is used to indicate that one end of an otherwise continuous chainterminates in (-9%!%-? group

)9/ I5$A- 2ystem)he system of nomenclature so devised is presently known as the I5$A- system.

2ystematic names or organic compounds consist of three main parts6$refix stem suffix

)he stem indicates the number of carbon atoms in the backbone or parent chain of the molecules.)he )arent chain is the longest continuous chain of carbon atoms.>ackbone 2tem >ackbone 2tem- 1 3et? - 11 5ndec?- " /th? - 1" ,odec?- % $rop - 1% )ridec?- >ut? -1 )etradec?- * $ent? -1* $entadec?- + 9ex? - 1+ 9exadec?- @ 9ept? - 1@ 9eptadec?- D =ct? -1D =ctadec?

$1





#lycogen stored food in animals2tarch stored food in plants-ellulose supporting framework of plants

Hucleotides-omponents1. Hitrogenous >ase (adenine4 guanine4 cytosine4 thymine4 uracil!". 2ugar moiety%. phosphate group

,HA deoxyribonucleic acid8HA ribonucleic acid

+! Hector and Scalar

(calar 0uantity a 0uantity which is expressed by magnitude only

/xamples6a! 3ass d! Areab! )ime e! ,istancec! )emperature

Vector 0uantity a 0uantity which is expressed by magnitude and direction

/xamples6a! &orce d! Accelerationb! Eelocity e! ,isplacementc! Ceight

• An arrow is used to represent a vector

$arts of the arrowa! arrowhead indicates the direction of the vector b! length of the arrow represents the magnitude of the vector c! )ail represents the origin of the vector

• 8esultant vector sum difference of two or more vectors which will give the same effect asthe original vectors.

$rocess of finding the resultant vector a! addition if vectors have the same direction

/xample6 Kelly walks " meters to the east. After 1; seconds4 he continued walking %meters to the same direction. Chat is his displacement:

, O "m L %m O *m to the east

5sing an arrow4 "m %m or *m

b! 2ubtraction if vectors are acting on opposite directions. )he resultant vector takes thedirection of the larger vector.

/xample6 A ball was tossed upward from the building and reached the height of *m abovethe building. It the moved downwards4 traveling 1;m until it hits the ground.

$3

Physics



, O ?1;m L *m O ?*m

5sing an arrow4

*m 1;m or 1*m

c! $ythagorean )heorem if vectors are acting at a right angle with one another

/xample6 3arivic first walks "km north before proceeding 1.* km east.Chat is her displacement:

( )$.1222 += D

, O ".* km

5sing an arrow41.*km

"km".*km

d! -omponent 3ethod if several vectors are acting on different directions4 x and ycomponent are mathematically added to find the resultant vector.

/xample6 An airplane flies in a northeasterly direction at 1;;kph at the same time thatthere is a wind blowing at ";kph to the northwest. Chat is the resultant velocity of theplane:

V?components6

Explane O LEplane cos * O @;.@1kphExwind O ?Ewind cos * O ?1 .1 kphP?components6

Eyplane O LEplane sin * O @;.@1kph

Eywind O LEwind sin *

O 1 .1 kph

8esultant Eelocity

Ex O Explane L Exwind O @;.@1 1 .1 O *+.*@ kphEy O Eyplane L Eywind O @;.@1 L 1 .1 O D .D*kph

$4



@! Mechanics

3otion change in position of an ob ect relative to other ob ects that are considered atrest.

• 7inear 3otion

Distance vs. Displacement

,istance total path length traveled by a body.

,isplacement change in position of an ob ect. It represents the straight line path betweenthe starting and end points.

/xample6a. Gen travels *km to work and back. Chat is the distance she travels: Chat is

the displacement:

,istance O *km L *km O 1;km

,isplacement O *km *km O ;

'since there is no change in position4 her displacement is zero

b. 8ocky walks "; km due north from his camp. 7ate in the afternoon4 he walksback 11km south along the same path.

i. Chat is his total displacement from the camp:ii. Chat is the total distance he traveled:

i. ,isplacement O ";km L (?11km! O <km due north

ii. ,istance O ";km L 11km O %1 km

(peed vs. Velocity

2peed measure of how fast an ob ect travelso Average speed ration of total distance traveled to the time needed to cover that

distance.

e ElapsedTimd ceTravelleTotalDis

ed AverageSpe tan=

/xample6 It takes a school bus 1 hour to travel ";km. Chat is its average speed:

hr km

hr km

ed AverageSpe 201

20==

o Instantaneous speed is the speed at particular instance in time

$$



Instantaneous 2peed12

12

t t

x x

t x

−

−=

∆

∆=

/xample6 Chat is the speed of a car that covered 1*;km in two hours:

Instantaneous 2peedhr km

hrskm

t x

,$0201$0 =

−

−=

∆

∆=

o Eelocity rate of motion with direction

timent displaceme

Velocity =

/xample6 8ocky drives a distance of D;km in " hours towards the north direction. Chatis his velocity:

#iven6d O D;kmt O "hrs

&ind6 v2olution6

hrskm

v2

80=

northhrskm

v 40=

o -cceleration rate of change of velocity

timelocityChangeOfVe

on Accelerati =

/xample6 A driver steadily increases his velocity from %;hr km

to +; hr km

in " hours.Chat is his acceleration:

21$

2

30%0

hr

km

hrshr km

hr km

a =

−

=

8ra)hs relatin" dis)lacement< ;elocity and acceleration

$%



# v a

ttt

ero acceleration ero velocit(

here # 3 displacement v 3 velocit( a 3 acceleration t 3 time

$,



# v a

ttt

ero acceleration constant velocit(


# v a

ttt

constant acceleration increasing velocit(


• Ideal linear motion

a! 5niform 3otion motion with constant velocity

Tx O vtChere

Tx O x xov O velocityt O time

$8



/xample6 Chat is the displacement of a car moving at a constant velocity of ";m safter " seconds:

#iven6v O ";m st O "s

&ind6 Tx

2olution6 Tx O vtTx O ";m s ("s!Tx O ;m

b! 5niform Accelerated 3otion motion with constant acceleration

at V V o f +=

2

2

t V X a

t X oo

++=

X aV V o f ∆+= 222

2

4t5# 66 of +=∆

Chere6Ef O final velocityEo O initial velocitya O accelerationt O timeV O final positionVo O initial positionTV O V Vo4displacement

/xample6 A cyclist is moving with a velocity of "m s and accelerates to m s after " seconds. Chais the acceleration of the cyclist:

#iven6Ef O m sEo O "m st O " s

&ind6 a

2olution6 at V V o f +=

t

45a 66 of −=

s

sm

2

'254m'sa +=

a O 1 m s"

$9



c! &reefall ? a good example of uniform accelerated motion ? one dimensional motion where the moving ob ect is only under the influence of gravity ? gravitational acceleration is e0ual to ?<.Dm s"

gt V V o f +=

2

2

t V Y g t Y oo ++=

Y g V V o f ∆+= 222

2

4t57 66 of +=∆

Chere6Ef O final velocityEo O initial velocityg O ?<.Dm s"4 gravitational accelerationt O timeP O final positionPo O initial positionTP O P Po4 displacement

/xample6 A ball is dropped from a building without an initial velocity. &ind the velocity of the bafter * seconds.

#iven6) O * sEo O ;

&ind6 Ef 2olution6Ef O gt O (?<.Dm s"! *s O ? <m s

/xample6 A mango falls from a tree. 9ow far does it fall after ;.* seconds:#iven6

t O ;.* sEo O ;

&ind6 TP2olution6

2

2t V g t Y o

+=∆

2

8.9 4$.05 2

2 s sm

Y

−

=∆

TP O ?1<.+ m%0



d! $ro ectile 3otion curved motion of an ob ect that is pro ected into the air and acted upon by thgravitational force of the earth

? a combination of uniform motion and freefall

$ro ectile an ob ect thrown into the air that is allowed to move freely and is influenced only gravity

h6o

*)

8ange horizontal distance covered by a pro ectile

)ime of flight time in which the pro ectile is up in the air

)ra ectory curve traced by the path of the pro ectile

3aximum height4 h the vertical displacement traveled by the pro ectile in its tra ectory

-onditions of $ro ectile 3otion throughout the flight6

a! Heglect the effect of air resistance to the body

b! )he horizontal and vertical motions are independent of each other. 2eparate the displacementand velocity to its x and y components.

Along the horizontal6

i! the x component of the velocity is constant throughout the flightii! the horizontal displacement x4 follows uniform motioniii! &ormula along the horizontal is the same as uniform motion

Along the vertical6

i! the y component of the velocity acts as freefall and thus4 only affected by thegravitational acceleration

ii! )he velocityBs sign is positive (L! for upward motion while for downward motion4 itnegative (?!.

iii! 5pon hitting the ground4 its velocity is always e0ual to zero.iv! )he time re0uired for the pro ectile to reach its maximum height from its firing point

e0ual to the time that the pro ectile will reach the same height of its firing point from thmaximum height.

v! &ormula along the vertical is the same as freefall%1



Chen vertical displacement is at its maximum height6

i! the x component of the velocity is constantii! the y component of the velocity is e0ual to zeroiii! the acceleration is still e0ual to g4?<.Dm s"

/xample6 A stone is thrown with an initial horizontal velocity of 1;m s from the top of a tower ";;m

high. Chere is the stone after "s: Chen will it hit the ground: Chat is its speed ust before it hitsthe ground:

#iven6Ex O 1;m sdy O ";;mt O "s&ind6 dx after "s4 t4 Ef 2olution6

i! Tx O vtTx O (1;m s!("s!Tx O ";m

ii!2

2

t V Y g

t Y oo

++=

2ince there is no initial velocity along the vertical and the top of the building is thereference point4 Po and Eyo is e0ual to zero.

g Y

t 2

=

sm

mt

28.9

420052

−

−=

t O +.%D s

iii! gt V V o f +=

38.%58.950 2

sm sV f −+=

smV f '$2.%2−=

7! Newton s Laws of Motion- explains why ob ects move4 and define the relationship between the external

forces acting on a body as well as between two or more interacting bodiesand the motion that arises from the action of these forces.

1. &irst 7aw of 3otion (7aw of Inertia!

JEvery material continues to be at rest if it is at rest or in uniform motion if it is inmotion unless it is compelled to change that state by forces acted upon it.

Inertia is the tendency of an ob ect to resist a change in its state of motion3ass is a measure of an ob ectBs inertia

%2



Ceight force acted upon an ob ect due to gravity&orce a push or a pull (e.g. gravitational force4 friction4 normal forces4 electromagnetforce4 etc.!

- a vector 0uantity with 2I unit of Hewton (H O kg?m s"!

". 2econd 7aw of 3otion (7aw of acceleration!

3"he acceleration of an object is directly proportional to the net force acting on the

object is in the direction of the net force and is inversely proportional to the massof the object.4

m F

a =

& O ma

' &orce and mass have opposite effect on acceleration. )he more massive the ob ect4 theless is the acceleration. )his means that acceleration is inversely proportional to the mass. )hegreater force will result to greater the acceleration. &orce is directly proportional to the accelerationof an ob ect.

/xample6 Heglecting friction4 what constant force will give a mass of *;kg an acceleration of

*m s"

:#iven6

m O *;kga O *m s"

&ind6 &2olution6

& O ma& O (*;kg!( *m s"!& O "*; kg?m s" or "*;H

%! )hird 7aw of 3otion (7aw of action?reaction!

35henever one object exerts a force on a second object the second object exertsan e0ual and opposite force.4

9ence4 if your hand exerts a force of ";H in a wall4 the wall will also exert a force of ";H inyour hand.

D! Momentum and Bm)ulse3omentum

3omentum is a physical 0uantity obtained when the mass of an ob ect is multiplied toits velocity. It has the same direction as the velocity. )his means that an ob ect with largemass and velocity has high momentum. Accordingly4 an ob ect at rest has a momentume0ual to zero.

p O mv

Chere6p O momentumm O massv O velocity

/xample6 A truck full of sand with a mass of ;4;;;kg travels east with a velocity of *;m s.Chat is the truckBs momentum:

#iven6m O ;4;;;kg

%3



v O *;m s&ind6 p2olution6

p O mvp O ( ;;;;kg! (*;m s!p O "4;;;4;;; kg?m s

Impulse

Impulse is a vector 0uantity that has the same direction as the force. It is e0ual to theproduct of force and time. It is also associated with the change of momentum.

mv ∆=

F mat vm

t mv

t

==∆

∆=

∆

∆=

∆

t F ∆=

Chere6G O impulse& O &orceTt O change in timem O massv O velocity

/xample6 A bat hits the baseball. )he bat and the baseball remain in contact for ;.;;*seconds. )he ;.1kg ball leaves the bat with a velocity of 1;;m s. Chat is the average forceof the bat on the baseball:

#iven6t O ;.;;*sm O ;.1kgv O 1;;m s

&ind6 &2olution6

t F mvmv

∆

−= 0

00$.0041001.05 −= x

F

! F 2000=

7aw of -onservation of 3omentum

J"he total momentum of a system remains constant if the net external forces

acting on the system are e0ual to $ero.

∑ ∑="efore after

mvmv

As stated4 the total linear momentum of the system does not change. )his means that if you add all the momenta4 you will get the same result even if the ob ects are colliding with eacother.

%4



-ollision any string interaction between two bodies that lasts a relatively short time)wo types of -ollision

i! /lastic collision after the collision4 the ob ects is still separatd from eachother

ii! Inelastic collision after the collision4 the ob ects move as one unit/xternal &orces &orces exerted on any part of the system by any body outside the system

/. Cork4 /nergy4 $ower

Cork the product of force and displacement

θ cos x F # ∆•=

Chere6C O work& O forceTx O displacement

H=)/6 A force does no work if it is perpendicular to the displacement

/xample6 A 1;;H block lies on a frictionless surface. A force of ";H was applied horizontally

where the block had moved *m. &ind the work done by the force and weight of the block.#iven6

Ceight of the block O 1;;H&orce applied O ";H,isplacement O *m

&ind6 Cork by the force and weight2olution6

i! θ cos x F # force ∆•=

0cos$20 m ! # force •=

o$les !m

# force100100 ==

ii! θ cos x F # %eight ∆•=

90cos0100 •=# %eight

0=# %eight

)he work done by the weight is e0ual to zero since it is perpendicular to the displacement.

/nergy capacity to do work ? a scalar 0uantity

)ypes of 3echanical /nergy

a $otential /nergy )he energy stored on an ob ect due to itsposition.

i! #ravitational $otential /nergymgh &E grav

=

Chere6

%$



$/ O $otential /nergym O massg O gravitational accelerationh O height

ii! /lastic $otential energy stored on an elastic material due to its stretching or compressing

xk &E s ∆=

2

2

1

Chere6$/ O $otential /nergyk O force constant of the springTx O extension compression of the spring

b Kinetic /nergy energy of an ob ect in motion

vm 'E 2

21=

Chere6K/ O Kinetic energym O massv O velocity

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