ChemistryChemistry

Diamond WaterDiamond Water SugarSugar

Diamond (carbon) = CDiamond (carbon) = CWater = HWater = H22OO

Sugar = CSugar = C66HH1212OO66

The combination of carbon and waterThe combination of carbon and water

contains the same elements as sugar.contains the same elements as sugar.

. Elements: can’t be broken into . Elements: can’t be broken into simpler substances (atoms.)simpler substances (atoms.)

Sugar + water…would you drink this?Sugar + water…would you drink this?Ash + water…would you drink this?Ash + water…would you drink this?Why? They contain the same elements Why? They contain the same elements

don’t they? Why don’t you get sugar when don’t they? Why don’t you get sugar when you mix water with the coal?you mix water with the coal?

The elements (carbon in coal; hydrogen The elements (carbon in coal; hydrogen and oxygen in water) only combine as and oxygen in water) only combine as sugar when chemical bonds formsugar when chemical bonds form

Sugar cannot be easily separated into its Sugar cannot be easily separated into its components.components.

So…Can you break So…Can you break goldgold down down into a simpler substance???into a simpler substance???

NO…because it is an element!NO…because it is an element!

All All nuclei nuclei contain positively charged particles contain positively charged particles called protons (called protons (pp++).).

The center of an atom is called the The center of an atom is called the nucleusnucleusThe structure of an atomThe structure of an atom

Most contain particles that have no charge, Most contain particles that have no charge, called neutrons (called neutrons (nn00).).

Atoms are the basic building blocks of all Atoms are the basic building blocks of all matter. matter.

Example: Carbon has 6 protons so its Example: Carbon has 6 protons so its atomic number is 6atomic number is 6

Nucleus

Electron energy levels

The space surrounding the nucleus contains The space surrounding the nucleus contains extremely small, negatively charged particles extremely small, negatively charged particles called electrons (called electrons (ee--)) This region of space This region of space

is an electron cloud. is an electron cloud. Because opposites Because opposites attract, the - attract, the - electrons are held in electrons are held in the electron cloud by the electron cloud by the + nucleus.the + nucleus.

Atoms contain equal Atoms contain equal numbers of electrons numbers of electrons and protons; and protons; therefore, they have therefore, they have no net charge.no net charge.

ParticleParticle LocationLocation ChargeCharge SymbolSymbol

ElectronElectron Surrounding Surrounding nucleusnucleus

-- ee--

NeutronNeutron NucleiNuclei NoneNone nnoo

ProtonProton NucleiNuclei ++ pp++

• A compound is a substance that is composed of atoms of two or more different elements that are chemically combined.

Compounds and BondingCompounds and Bonding

• Table salt (NaCl) is a compound composed of the elements sodium and chlorine.

• A covalent bond holds the two hydrogen atoms together.

How covalent bonds formHow covalent bonds form

• A molecule is a group of atoms held together by covalent bonds.

It has no overall charge.

Water molecule

2 electrons in the 12 electrons in the 1stst electron electron shellshell

8 electrons in the 28 electrons in the 2ndnd electron electron shellshell

18 electrons in the 318 electrons in the 3rdrd electron electron shellshell

Pentacene is a polycyclic aromatic hydrocarbon consisting of five linearly-fused benzene rings. Used in dyes and solar cells.

•This is an actual picture (the 1st EVER) of a molecule. This is a picture of the smallest thing ever taken!

•Not notes! Just cool

• An atom (or group of atoms) that gains or loses electrons has an electrical charge and is called an ion. An ion is a charged particle made of atoms.

How ionic bonds formHow ionic bonds form

• The attractive force between two ions of opposite charge is known as an ionic bond.

• In a chemical reaction, substances that undergo chemical reactions, are called reactants.

Writing chemical equationsWriting chemical equations

• Substances formed by chemical reactions, are called products.•COCO22 + H + H22O-----yields----HO-----yields----H22COCO33 (carbonic acid) is (carbonic acid) is a sample chemical reaction in living things a sample chemical reaction in living things

•ReactantsReactants are on the are on the leftleft side of the equation, side of the equation, while while productsproducts are on the are on the rightright side side

• A molecule of table sugar can be represented by the formula: C12H22O11.

Writing chemical equationsWriting chemical equations

•Atoms are neither created nor destroyed in chemical reactions. They are simply rearranged.

•A mixture is a combination of substances in which the individual components retain their own properties.

• Neither component of the mixture changes.

Ex: sand + sugar Ex: sand + sugar

Heterogeneous MixturesHeterogeneous Mixtures A mixture that is NOT mixed A mixture that is NOT mixed

evenly throughout evenly throughout & each & each component keeps component keeps its own its own properties.properties.

•RocksRocks •SaladSalad •Chicken NoodleChicken Noodle

•SoupSoup

• A solution is a mixture in which one or more substances (solutes) are distributed evenly in another substance (solvent).

Mixtures and SolutionsMixtures and Solutions

•Ex. Sugar + Water + Kool Aid

•Can’t separate

Solid Solid Matter with definite shape & volume.Matter with definite shape & volume. Tightly packed particles that mainly Tightly packed particles that mainly

vibrate.vibrate.

Phases of MatterPhases of Matter

GasGas Matter that doesn’t Matter that doesn’t have definite have definite volume or shape.volume or shape.

Particles move at Particles move at high speeds in all high speeds in all directionsdirections

LiquidLiquid

• Matter with a Matter with a definite volume definite volume but no definite but no definite shape.shape.

• Particles flow Particles flow freely from one freely from one place to another.place to another.

•gas•liquid •solid

Heating Curve of WaterHeating Curve of Water

•-20oC

•0oC

•100oC

•Time (Increasing)

•Heat Energy (Increasing)

PlasmaPlasma

• State of State of electrically charged electrically charged free moving free moving particles.particles.

Physical ChangesPhysical ChangesThe form or appearance of matter The form or appearance of matter changes, but not its composition.changes, but not its composition.

DissolvingDissolvingChanging State/PhaseChanging State/PhaseAbsorptionAbsorptionCutting/Tearing/SmashingCutting/Tearing/Smashing

Chemical ChangesChemical ChangesChanging from one substance into Changing from one substance into a new substance.a new substance.

Color changeColor changeForming a gas or solidForming a gas or solidProducing lightProducing lightOdorsOdorsGiving off heat Giving off heat Absorbing heatAbsorbing heat

Classification of the ElementsClassification of the Elements MetalsMetals

Most of the elements are solid metals.Most of the elements are solid metals.Metals are usually shiny, malleable, good Metals are usually shiny, malleable, good

conductors of heat & electricity and conductors of heat & electricity and ductile.ductile.

MetalloidsMetalloidsElements that have some characteristics Elements that have some characteristics

of both metals & nonmetals.of both metals & nonmetals.- Examples: Boron, Silicon, Antimony, - Examples: Boron, Silicon, Antimony,

& Arsenic & Arsenic

The Periodic TableThe Periodic Table

NonmetalsNonmetalsMost nonmetals Most nonmetals

are gases.are gases.Solid nonmetals Solid nonmetals

are brittle, poor are brittle, poor conductors, & not conductors, & not easily shaped.easily shaped.

97% of your body 97% of your body is made of is made of nonmetalsnonmetals

•Sulfur

•Liquid O2

EElementslements

Atomic NumberAtomic Number Shows the number of protons in the nucleus.Shows the number of protons in the nucleus.Every atom of that element has only that Every atom of that element has only that

number of protons.number of protons.

Mass NumberMass Number Number of protons plus neutrons.Number of protons plus neutrons. IsotopesIsotopes: Atoms of the same element with : Atoms of the same element with

different numbers of different numbers of neutrons.neutrons.

Examples: Examples: Hydrogen-1, Hydrogen-2, Hydrogen-3 Hydrogen-1, Hydrogen-2, Hydrogen-3 Carbon-12, Carbon-14 Carbon-12, Carbon-14

Used to treat cancer & radioactive datingUsed to treat cancer & radioactive dating

Atomic MassAtomic Mass The weighted average of the isotopes The weighted average of the isotopes

of an element.of an element.Measured in Measured in mass unitsmass units (u) (u)

•AgAg•4747

•SilverSilver

•107.868107.868•Atomic Mass

•Atomic Number

•Chemical

•Symbol

The Periodic TableThe Periodic Table* * Arranged according to atomic number Arranged according to atomic number

and similar properties. and similar properties.

PeriodsPeriods A row (horizontal) of elements.A row (horizontal) of elements.The properties gradually change The properties gradually change

predictably across the period.predictably across the period.

Groups/FamiliesGroups/Families Usually the vertical columns of Usually the vertical columns of

elements that have similar physical & elements that have similar physical & chemical properties.chemical properties.

Alkali MetalsAlkali Metals Most reactive of the elements.Most reactive of the elements. Not naturally found by itself.Not naturally found by itself. Has a single electron in its outermost shell.Has a single electron in its outermost shell.Column #1Column #1

Alkaline Earth MetalsAlkaline Earth Metals Commonly used in fireworks for the colors.Commonly used in fireworks for the colors. Has 2 electrons in the outermost shell.Has 2 electrons in the outermost shell.Column #2Column #2

3

Li11

Na

19

K37

Rb

55

Cs

87

Fr

4

Be

12

Mg

20

Ca

38

Sr56

Ba

88

Ra

HalogensHalogens Bond with Alkali Metals Bond with Alkali Metals

to form salts.to form salts. Have 7 electrons in Have 7 electrons in

outermost shell.outermost shell. Steal electrons from Steal electrons from

other atoms.other atoms. Column #17Column #17

9

F17

Cl35

Br53

I85

At117

Transition ElementsTransition Elements• Wide variety of metals such Wide variety of metals such as coin & structural metals.as coin & structural metals.

• Middle of the periodic table.Middle of the periodic table.

• Examples: Gold, Silver, Examples: Gold, Silver, Mercury,Mercury, Lead, & CopperLead, & Copper

Noble GasesNoble Gases Only naturally stable elements.Only naturally stable elements. Have a full outermost shell of electrons (8)Have a full outermost shell of electrons (8) Found in small amounts in the atmosphere.Found in small amounts in the atmosphere. Heated to produce colorful light.Heated to produce colorful light. Column #18Column #18

2

He

10

Ne18

Ar36

Kr

54

Xe86

Rn

118

Carbon CompoundsCarbon CompoundsFoundation for lifeFoundation for lifeCarbohydrates, Lipids/Fats, Proteins, & Carbohydrates, Lipids/Fats, Proteins, &

Amino Acids.Amino Acids.Hydrocarbons - long chains of Hydrogen Hydrocarbons - long chains of Hydrogen

& Carbon atoms :Alcohols & Fuels& Carbon atoms :Alcohols & Fuels

Law of Conservation of MassLaw of Conservation of MassThe mass of the reactants will equal the mass The mass of the reactants will equal the mass

of the products.of the products.

Energy in ReactionsEnergy in Reactions1. 1. EndothermicEndothermic –– reaction where energy reaction where energy

is absorbed. is absorbed.

2H2H22O + energyO + energy 2H2H22 + O + O22

22. . ExothermicExothermic –– reaction where energy is reaction where energy is released. released.

CC66HH1212OO66 + O + O22 H H22O + COO + CO22 + energy + energy

Rates of Reaction (things that affect Rates of Reaction (things that affect the rate)the rate)

1. Temperature1. Temperature

2. Surface Area2. Surface Area

3. Pressure3. Pressure

4. 4. CatalystCatalyst – – a substance that speeds a substance that speeds up a chemical reaction. (Enzymes)up a chemical reaction. (Enzymes)

• Water resists changes in temperature.

WaterWater

• Water is one of the few substances that expands when it freezes.

• Ice is less dense than liquid water so it floats as it forms in a body of water.

Adhesion and CohesionAdhesion and Cohesion

Water is attracted to other water. This is Water is attracted to other water. This is called called cohesioncohesion. .

Water can also be attracted to other Water can also be attracted to other materials. This is called materials. This is called adhesionadhesion. .

Caused by adhesion the water runs along the glass and does not fall straight.

water on a penny!

Fin