Periodic TablePeriodic Table

A Closer LookA Closer Look

History of the Periodic TableHistory of the Periodic Table

Mendeleev arranged Mendeleev arranged the elements into the the elements into the world’s 1world’s 1stst periodic periodic tabletable Increasing atomic Increasing atomic

massmass Atomic mass was Atomic mass was

known by comparing known by comparing the amounts of the amounts of elements that reacted elements that reacted with each otherwith each other

Modern Periodic TableModern Periodic Table

Not identical to Not identical to Mendeleev’s table – Mendeleev’s table – he didn’t know about he didn’t know about protons and electronsprotons and electrons

Increasing atomic Increasing atomic number instead of number instead of massmass Number of protonsNumber of protons Number of electronsNumber of electrons

GroupsGroups

Columns on the tableColumns on the table Same number of Same number of

valence electronsvalence electrons Similar chemical Similar chemical

propertiesproperties Similar physical Similar physical

propertiesproperties

More reactive as you More reactive as you go down in a groupgo down in a group Group 1 – Alkali metals

Stored in oil so they won’t react with the air

Valence ElectronsValence Electrons

Outermost electronsOutermost electrons They participate in all They participate in all

chemical bondschemical bonds Every atom “wants” Every atom “wants”

eight valence eight valence electronselectrons

Noble gases already Noble gases already have eight valence have eight valence electrons – least electrons – least reactive elementsreactive elements

GroupsGroups

Numbered left to rightNumbered left to right Group 1 – alkali metalsGroup 1 – alkali metals Group 2 – alkaline earth metalsGroup 2 – alkaline earth metals Groups 3 to 12 – transition Groups 3 to 12 – transition

metalsmetals Groups 13 to 16 – metals, Groups 13 to 16 – metals,

metalloids, & nonmetalsmetalloids, & nonmetals Group 17 – halogensGroup 17 – halogens Group 18 – noble gasesGroup 18 – noble gases

Group 3Group 3

ScandiumScandium

YttriumYttrium

LanthanumLanthanum

ActiniumActinium

PeriodsPeriods

Horizontal rowsHorizontal rows The two at the bottom The two at the bottom

are part of rows 6 & 7are part of rows 6 & 7 Same number of Same number of

energy levelsenergy levels Properties change in Properties change in

the same way across the same way across each row (periodic each row (periodic law)law)

Period 3Period 3

LithiumLithium BerylliumBeryllium BoronBoron CarbonCarbon NitrogenNitrogen OxygenOxygen FluorineFluorine Neon Neon

General CategoriesGeneral Categories

MetalsMetals ShinyShiny

ConductorsConductors

DuctileDuctile

Malleable Malleable

NonmetalsNonmetals DullDull

InsultatorsInsultators

BrittleBrittle

MetalloidsMetalloids Properties of bothProperties of both

Placement on the Periodic TablePlacement on the Periodic Table

Metals

Metalloids

Nonmetals

Period 4, Group 1 contains K, which is potassium

Properties of MetalsProperties of Metals

ShinyShiny

ConductorsConductors

DuctileDuctile

Malleable Malleable

Metallic ElementsMetallic Elements

Metallic properties Metallic properties increase as you increase as you move down and to move down and to the leftthe left

Most metallic Most metallic elements are in elements are in group 1group 1

Alkali MetalsAlkali Metals

Group 1Group 1LiLiNaNaKKRbRbCsCsFrFr

Very reactiveVery reactive Easily lose one Easily lose one

valence electronvalence electron The further out the The further out the

electron is from the electron is from the nucleus the easier it is nucleus the easier it is to lose itto lose it

Reactivity increases Reactivity increases as you go down in the as you go down in the groupgroup

Alkaline Earth MetalsAlkaline Earth Metals

Group 2Group 2BeBeMgMgCaCaSrSrBaBaRaRa

Properties of Alkaline Earth MetalsProperties of Alkaline Earth Metals

Less reactive than Less reactive than alkali metalsalkali metalsDon’t reactive as Don’t reactive as

violently with waterviolently with waterNeed more energy Need more energy

to begin their to begin their reactionsreactions

Lose two valence Lose two valence electronselectrons

Transition MetalsTransition MetalsGroups 3 to 12Groups 3 to 12AKA “heavy metals”AKA “heavy metals”

Large nucleiLarge nucleiForm colored compoundsForm colored compounds

AlloysAlloys

Homogeneous mixture of metalsHomogeneous mixture of metals Mix together metals to get the exact properties you Mix together metals to get the exact properties you

wantwant

Instruments, jewelry, construction, etc.Instruments, jewelry, construction, etc.

Sterling silver, brass, bronze, steelSterling silver, brass, bronze, steel

Coinage MetalsCoinage Metals

Resistant to Resistant to corrosioncorrosion

ExpensiveExpensiveFound in pure formFound in pure formThree – Three –

CopperCopperSilverSilverGoldGold

Rare Earth MetalsRare Earth Metals

Long Periodic TableLong Periodic Table

This is too long for practical use, so we pull the two rows out and put them at the bottom of the table.

Transuranium ElementsTransuranium Elements

Elements past Elements past uraniumuraniumAtomic numbers Atomic numbers

higher than 92higher than 92

RadioactiveRadioactive

Very short half livesVery short half livesNot found in natureNot found in nature

Created in laboratoriesCreated in laboratories

RadioactivityRadioactivity

One element turning into another elementOne element turning into another elementHalf life = how fast the element changesHalf life = how fast the element changes

MetalloidsMetalloidsThis line separates the metals from the nonmetals on the periodic table

These are the metalloids•B•Si•Ge• As•Sb•Te•Po

SemiconductorsSemiconductors

MetalloidsMetalloidsOnly let electricity Only let electricity

through in one through in one directiondirection

Used in modern Used in modern electronics electronics Cell phonesCell phonesVideo gamesVideo gamesComputer chipsComputer chips

Organic CompoundsOrganic Compounds

Historically Historically believed to be believed to be created only by created only by living organismsliving organisms

Contain carbon, Contain carbon, hydrogen, oxygen, hydrogen, oxygen, nitrogen and sulfurnitrogen and sulfur

Chocolate

Nonmetallic ElementsNonmetallic Elements

InsultatorsInsultators

Brittle Brittle

DullDull

HalogensHalogens

Group 17Group 17FFClClBrBr II

““Salt forming”Salt forming”Most reactive Most reactive

nonmetalsnonmetals

Reactivity of HalogensReactivity of Halogens

Combine with Combine with metals to form metals to form compounds called compounds called saltssaltsSodium chlorideSodium chlorideMagnesium iodideMagnesium iodide

Fluorine is the Fluorine is the most reactive most reactive element on Earthelement on Earth

Noble GasesNoble Gases

Group 18Group 18HeHeNeNeArAr

Eight valence Eight valence electrons, so electrons, so they don’t react they don’t react with anythingwith anything

KrKrXeXeRnRn