Chapter 3Chapter 3Elements & The Periodic TableElements & The Periodic Table

Section 1Section 1Introduction to AtomsIntroduction to Atoms

MatterMatter Anything that has mass and takes up Anything that has mass and takes up

space.space. Atom-basic part of matterAtom-basic part of matter

Atom means Atom means indivisibleindivisible (can’t be divided) in Greek. (can’t be divided) in Greek.

Atomic Theory-Atomic Theory-atomsatoms are the building are the building blocks of matter.blocks of matter.

Structure of the AtomStructure of the Atom

Made up of 3 small Made up of 3 small parts.parts.

1. Protons1. Protons

2. Neutrons2. Neutrons

3. Electrons3. Electrons

ProtonsProtons

Found in the nucleusFound in the nucleus Have a Have a positive positive charge (+)charge (+)

NeutronsNeutrons

Also found in Also found in the nucleusthe nucleus

No charge- No charge- neutralneutral

ElectronsElectrons Found on energy levels Found on energy levels

outsideoutside the nucleus. the nucleus. Has a Has a negativenegative charge charge

(-)(-) Electrons are the Electrons are the

smallest part of an smallest part of an atom.atom.

Found on energy levelsFound on energy levels Also known as energy Also known as energy

rings/electron cloudrings/electron cloud

Energy Levels of ElectronsEnergy Levels of Electrons

Surround the Surround the nucleus.nucleus.

The number of The number of electrons on each electrons on each energy level are: energy level are: 2,8,18,32,32,18,8,22,8,18,32,32,18,8,2

Must fill up energy Must fill up energy ring before going to ring before going to the next ring.the next ring.

Last ring are Last ring are valance valance electrons.electrons.

Mass of an Atom Mass of an Atom (Atomic Mass)(Atomic Mass)

Equal to the Equal to the number of number of particles in the particles in the nucleus.nucleus.

Protons + Protons + Neutrons = MassNeutrons = Mass

Atomic NumberAtomic Number

The number of The number of protonsprotons ANDAND the the number of number of electronselectrons..

Protons and Protons and electrons are electrons are alwaysalways the same the same number. number.

Atoms and ElementsAtoms and Elements

There must be an equal amount of positive There must be an equal amount of positive and negative charges.and negative charges.

Because of this……Because of this…… ATOMS ARE ALWAYS NEUTRAL, THEY ATOMS ARE ALWAYS NEUTRAL, THEY

HAVE NO CHARGE.HAVE NO CHARGE.

Mass Number and IsotopesMass Number and Isotopes

IsotopesIsotopes-atom of the same element with a -atom of the same element with a different number of neutrons.different number of neutrons.

Isotopes that are in nature are unstable.Isotopes that are in nature are unstable. They are radioactiveThey are radioactive The number of neutrons does not affect the The number of neutrons does not affect the

charge, only the mass.charge, only the mass. The mass number helps tell one isotope from The mass number helps tell one isotope from

another.another.

Example of IsotopesExample of Isotopes

Section 2-Organizing the Section 2-Organizing the ElementsElements

Periodic-to have a Periodic-to have a regular repeating regular repeating pattern.pattern.

Dmitri Mendeleev-Dmitri Mendeleev- created the first created the first periodic tableperiodic table Ordered the table from Ordered the table from

lowest to highest masslowest to highest mass (Big Problem)-they all (Big Problem)-they all didn’t fit in the right didn’t fit in the right spots.spots.

Henry Moseley- Henry Moseley- arranged the arranged the elements in order of elements in order of increasing atomic increasing atomic number.number.

He designed the He designed the modern periodic modern periodic table.table.

He discovered this He discovered this pattern had no pattern had no irregularities.irregularities.

Columns and RowsColumns and Rows Columns (groups)-Columns (groups)-represent elements with represent elements with

similar properties and electron arrangements.similar properties and electron arrangements. Rows (periods)-Rows (periods)-represent increasing atomic represent increasing atomic

number, go from metals to nonmetals.number, go from metals to nonmetals.

Section 3-MetalsSection 3-Metals Properties of Metals:Properties of Metals:

LusterLuster: Surface will reflect light (shiny): Surface will reflect light (shiny) Conduct heat and electricityConduct heat and electricity Useful to make cooking utensils and wireUseful to make cooking utensils and wire High melting point (except pure gold and pure High melting point (except pure gold and pure

silver) because they are soft metals.silver) because they are soft metals. Pure gold and pure silver are not used alone in Pure gold and pure silver are not used alone in

jewelry and coins, they are combined.jewelry and coins, they are combined. Gallium melts at room temperature.Gallium melts at room temperature. Mercury is a liquid at room temperature.Mercury is a liquid at room temperature.

MalleabilityMalleability

Most useful property Most useful property of a metal.of a metal.

Can be flattened, Can be flattened, bent, and shaped bent, and shaped without breaking.without breaking.

DuctileDuctile-can be pulled -can be pulled into wire.into wire.

Alkali Metals: Group 1Alkali Metals: Group 1 Li, Na, K, Rb, Cs, FrLi, Na, K, Rb, Cs, Fr Most reactiveMost reactive Combine very easily with Combine very easily with

other elementsother elements All have one electron in All have one electron in

the outer shellthe outer shell Found in natureFound in nature ALWAYSALWAYS found in found in

compoundscompounds Combine to form saltsCombine to form salts Soft and easily cut with a Soft and easily cut with a

knifeknife Low densityLow density Melt at low temperaturesMelt at low temperatures

Alkaline Earth Metals: Group 2Alkaline Earth Metals: Group 2 Reactive, but not as reactive Reactive, but not as reactive

as group 1as group 1 2 valence electrons2 valence electrons Occur in nature and combine Occur in nature and combine

with other elementswith other elements Magnesium and calcium Magnesium and calcium are are

the most commonthe most common Calcium makes up bones Calcium makes up bones

and teethand teeth Used for building materials Used for building materials

such as cement.such as cement. Used for medicine-Used for medicine-

Magnesium hydroxide-milk of Magnesium hydroxide-milk of magnesia used for upset magnesia used for upset stomachsstomachs

Transition MetalsTransition Metals Most of the elements Most of the elements

fall into this groupfall into this group Hard and shinyHard and shiny High melting pointHigh melting point Good conductors of Good conductors of

electricityelectricity Less reactive, but can Less reactive, but can

combine with other combine with other elementselements

Fe, Co, Ni are magneticFe, Co, Ni are magnetic Found in ores-minerals Found in ores-minerals

containing large containing large amount of metal amount of metal compoundscompounds

Rare-Earth MetalsRare-Earth Metals Separate rows at the Separate rows at the

bottom of the bottom of the periodic tableperiodic table

Lanthanides Lanthanides Elements 58-71 Elements 58-71

except 61 occur in except 61 occur in naturenature

Occur in small Occur in small amounts in the amounts in the earth’s crustearth’s crust

Small amounts Small amounts are used in lasersare used in lasers

Create the red Create the red color in TVcolor in TV

OtherOther

Actinides-the rest of the periodic tableActinides-the rest of the periodic table Man made (Synthetic)Man made (Synthetic)

Nonmetals Nonmetals PropertiesProperties

No lusterNo luster Poor conductorsPoor conductors Dull and brittleDull and brittle Many are gases Many are gases

at room at room temperaturetemperature

Have many Have many electrons in their electrons in their outer shellouter shell

Located to right Located to right of the zigzag lineof the zigzag line

MetalloidsMetalloids PropertiesProperties

Shiny, but not Shiny, but not much lustermuch luster

Conduct heat Conduct heat and electricity, and electricity, but not as good but not as good as metalsas metals

SemiconductorsSemiconductors-Ex. Silicon will -Ex. Silicon will conduct conduct electricity only at electricity only at certain certain temperatures.temperatures.

Boron GroupBoron Group

Only element in group 13 that is not a metalOnly element in group 13 that is not a metal Brittle black metalloidBrittle black metalloid Aluminum is the most abundant metal on Aluminum is the most abundant metal on

Earth.Earth.

Carbon GroupCarbon Group

Only nonmetal Only nonmetal in group 14in group 14

Found in Found in ALLALL living thingsliving things

2 forms: 2 forms: Graphite Graphite

(pencils)(pencils) DiamondsDiamonds

Nitrogen GroupNitrogen Group

Only gas in Only gas in group15group15

80% of the 80% of the air we air we breathebreathe

Essential to Essential to living things living things and for and for making making proteinsproteins

Oxygen GroupOxygen Group

Only gas in group 16Only gas in group 16 Most abundant element on EarthMost abundant element on Earth Most important elementMost important element

Halogen GroupHalogen Group Known as salt Known as salt

formersformers Elements in group Elements in group

1717 Found in most foods Found in most foods

that we eatthat we eat Combine with Combine with

metals to form saltsmetals to form salts What metals do they What metals do they

combine with?combine with?

Noble GasesNoble Gases

Group 18Group 18 Contains 6 Contains 6

colorless gasescolorless gases DO NOT combine DO NOT combine

with any other with any other elementselements

All exist in the All exist in the Earth’s Earth’s atmosphereatmosphere

HydrogenHydrogen

Properties do not fit with any other groupProperties do not fit with any other group Reacts easily with other elementsReacts easily with other elements Can act as a metal or a nonmetalCan act as a metal or a nonmetal