Download UNIT 6- The Periodic Table CP Chemistry_CLASS NOTES.pptx

UNIT6:ThePeriodicTable
CPChemistry
GHS
ì
Objectives
ì  Explainorganiza8onofperiodictableinperiodsandgroups.
ì  Iden8fyelementsasbelongingtorepresenta8veelements,transi8on
elements,metals,nonmetals,ormetalloids.
ì  Describeproper8esofmetals,nonmetals,andmetalloids.
ì  Describeproper8esofalkalimetals,alkalineearthmetals,halogens,and
noblegases.
ì  Describetrendsinmetallicproper8es,atomicradius,ioniza8onenergy,
andelectronega8vitythroughgroupsandperiodsintheperiodictable.
ì  Explainperiodictrendsintermsoftherela8onshipbetweensubatomic
par8cleaErac8on/repulsionandshieldingeffect.
Whatwealreadyknow
ì  Ma#erisanythingthattakesupspaceand
hasmass.
ì  AllmaEerismadeofatoms
ì  Atomsarethe“buildingblocks”
ì  Butwhatisanatom?
AtomicStructure
~Theparts~
ì  Anatomhas3mainparts
Proton=posi8vecharge
Neutron =nocharge(neutral)
Electron=nega8vecharge
Thenucleus(center)oftheatomsistheloca8onforprotonsand
neutrons.
Electronsorbitaroundthenucleus(inacloud)
Elements
ì  Theelements,aloneor
incombina8ons,make
upourbodies,our
world,oursun,andin
fact,theen8re
universe
PeriodicTable
ì  Theperiodictableorganizestheelementsina
par8cularway.
ì  Onecangatherinferinforma8onaboutanelement
justfromitsposi8onintheperiodtable!
ì  WHATCANYOUPREDICT?
ì  PhysicalproperAesofelements
ì  ChemicalreacAvityofelements
WhowasMendeleev?
ì  In1869,DmitriIvanovitchMendeléev
createdthefirstacceptedversionofthe
periodictable
ì  Hegroupedelementsaccordingtotheir
atomicmass
ì  Hediscoveredthatthegroups(families)
hadsimilarchemicalproperAes
ì  BlankspaceswereleZopentoaddnew
elements–thesehadn’tbeen
discoveredorcreatedyet,butheknew
theywouldbe!(SMARTGUY!)
WhoisHenryMosley?
ì  HenryMosleyarranged
theperiodictable
accordingtoatomic
number.
ì  Thischangeestablished
periodiclaw:the
proper8esofthe
elementsareperiodic
func8onsoftheiratomic
number.
Valenceelectrons
ì  Outermostelectronsinanatom
ì  ThePeriodicTablepredictshowmanyelectrons
tendtobelostorgainedforanatom
ì  Involvedinchemicalreac8ons(bonding)
Determining#ofValenceElectrons
UsingthePeriodicTable
OCTETRULE
ì  TheOCTETRULE:Atomstendtogain,lose,orshareelectrons
un8ltheyaresurroundedby8valenceelectrons.
ì  Thisistoachievethesameelectronconfigura8onasthe
atom’sclosestnoblegasontheperiodictableforgreatest
stability!
ì  EXAMPLE:H2Oshareselectrons
Ions~Gainingorlosinganelectron
ì  Inchemicalreac8ons,atomsmaygainorloseelectrons
ì  IONSareelementsthathavegainedorlostofoneormore
electronsresul8ginanetelectriccharge
ì  Lossofelectron=netchangeof+1foreachelectron
ì  Gainofelectron=netchangeof-1foreachelectron
Posi8velychargedions(Li+)areca8ons
Nega8velychargedions(F-)areanions
Ions
ì  Lossofelectron=netchangeof+1foreachelectron
Posi8velychargedions(Al3+)arecaAons
ì  Gainofelectron=netchangeof-1foreachelectron
Nega8velychargedions(Cl-)areanions
PredictingIONICCHARGE
UsingthePeriodicTable
PropertiesofMetals
ì  Metalsaregoodconductors
ì 
ì 
ì 
ì 
ofheatandelectricity.
Metalsareshiny(high
luster)
MetalsareducAle(canbe
stretchedintothinwires)
Metalsaremalleable(can
bepoundedintothin
sheets)
Achemicalpropertyof
metalisitsreac8onwith
waterwhichresultsin
corrosion
PropertiesofNon-Metals
ì  Non-metalsarePOOR
conductorsofheatand
electricity
ì  Non-metalsareNOTduc8le
ormalleable
ì  Solidnon-metalsarebri#le
(breakeasily)
ì  Theyaredull(lowluster!)
Sulfur
ì  Manynon-metalsare
GASES!
PropertiesofMetalloids
ì  Metalloids(metal-like)
havesomeproper8esof
BOTHmetalsandnonmetals
ì  TheyareSOLIDSthatcan
beshinyORdull
ì  Theyconductheatand
electricitybeEerthan
non-metalsbutnotas
wellasmetals
ì  TheyareducAleand
malleable
Silicon
GROUPS(Families)Periods
ì  Columnsofelementsarecalled
ì  Eachhorizontalrowofelementsis
ì  Elementsineachgrouphave
ì  Theelementsinaperiodarenot
groupsorfamilies.
similarbutnotiden%calproper8es
ì  Forexample,lithium(Li),sodium
calledaperiod
alikeinproper8es
ì  Theproper8eschangegreatly
acrossagivenrow
(Na),potassium(K),andother
membersofgroupIAareallsoZ,
white,shinymetals
ì  TheFIRSTelementinaperiodis
ì  Allelementsinagrouphavethe
ì  TheLASTelementinaperiodis
samenumberofvalence
electrons
alwaysanextremelyac8vesolid
alwaysaninertgas
*Inert=nonreac8ve
Hydrogen
ì  Thehydrogenislocatedattopofgroup1,
butitisnotamemberofthatfamily.
Hydrogenisinaclassofitsown.
ì  Existsasagasatroomtemperature.
ì  Ithasoneprotonandoneelectronin1st
energylevel
ì  Hydrogenonlyneeds2electronsto
completeits‘octet’rule(fillits1sorbital)
AlkaliMetals
ì  Thealkalimetalsareinthe
firstcolumnoftheperiodic
table,Group1.
ì  Atomsofthealkalimetals
haveasingleelectronintheir
outermostlevel.Theyhave1
valenceelectron.
ì  Proper8es:shiny,havethe
consistencyofclay,andare
easilycutwithaknife.
AlkaliMetals
ì  Theyarethemost
reacAvemetals
ì  Theyreactviolently
withwater
ì  Alkalimetalsare
neverfoundasfree
elementsinnature.
Theyarealways
bondedwithanother
element.
Whatdoesitmeanforanelement
tobeREACTIVE?
ì  Wewillbedescribingelementsaccordingtotheir
reacAvity
ì  Elementsthatarereac8vebondeasilywithother
elementstomakecompounds
Whatdoesitmeantobereactive?
ì  WhatmakesanelementreacAve?
ì  Incompletevalenceelectron
level
ì  Allatoms(excepthydrogen)
‘want’tohave8electronsin
theirveryoutermostenergy
level(ThisiscalledtheOCTET
RULE)
ì  Atomsbondun8lthislevelis
complete
AlkalineEarthMetals
ì  Theyareneverfounduncombinedinnature.
ì  Shinysolids.
ì  Theyhavetwovalenceelectrons.
ì  Veryreac8ve(formionswith2+charge)
ì  Alkalineearthmetalsincludemagnesiumandcalcium,
amongothers.
TransitionMetals
ì  TransiAonElementsinclude
thoseelementsintheBfamilies.
ì  Proper8esaresimilartoone
anotherandtoothermetals,but
theirproper8esdonotfitinwith
thoseofanyotherfamily.
ì  Metalsyouareprobablymost
familiar:copper,8n,zinc,iron,
nickel,gold,andsilver.
ì  Goodconductorsofheatand
electricity.
TransitionMetals
ì  Thecompoundsoftransi8onmetals
areusuallybrightlycoloredandare
oZenusedtocolorpaints.
ì  Transi8onelementshave1or2
valenceelectrons,whichtheylose
whentheyformbondswithother
atoms.
ì  Manytransi8onmetalscombine
chemicallywithoxygentoform
compoundscalledoxides
ì  SometransiAonelementscanlose
electronsintheirnext-to-outermost
level.
BoronFamily
ì  TheBoronFamilyisnamed
aZerthefirstelementinthe
family.
ì  3valenceelectrons.
ì  Tendtoformionswith3+
charge
ì  Includesametalloid(boron),
andtherestaremetals.
ì  Includesthemostabundant
metalintheearth’scrust
(aluminum)
CarbonFamily
ì  4valenceelectrons.
ì  Thisfamilyincludesanon-metal
(carbon),metalloids,andmetals.
ì  Theelementcarboniscalledthe“basis
oflife”
ì  Tendtoshareelectronswhenthey
bond
ì  Thereisanen8rebranchofchemistry
devotedtocarboncompoundscalled
organicchemistry!
NitrogenFamily
ì  ThenitrogenfamilyisnamedaZer
theelementthatmakesup78%of
ouratmosphere.
ì  Includesnon-metals,metalloids,
andmetals.
ì  5valenceelectrons.
ì  Theytendtoshareelectronswhen
theybond.
ì  Otherelementsinthisfamilyare
phosphorus,arsenic,an8mony,
andbismuth.
OxygenFamily
ì  6valenceelectrons.
ì  Mostelementsinthisfamilyshare
electronswhenforming
compounds.
ì  Oxygenisthemostabundant
elementintheearth’scrust.
ì  Extremelyac8veandcombines
withalmostallelements.
HalogenFamily
ì  Theelementsinthisfamilyare
fluorine,chlorine,bromine,
iodine,andasta8ne.
ì  7valenceelectrons.
ì  MOSTREACTIVEnon-metals.
ì  Halogenatomsonlyneedtogain
1electrontofilltheiroutermost
energylevel.
ì  Theyreactwithalkalimetalsto
formsalts.
ì  Theyareneverfoundfreein
nature.
NobleGases
ì  Colorlessgasesthatareextremelyun-
reacAve.
ì  Runningelectricitythroughproduces
color.
ì  Inac8vebecausetheiroutermost
energylevelisfull.(Moststable
configura8on.)
ì  Donotreadilycombinewithother
elementstoformcompounds=inert
ì  Thefamilyofnoblegasesincludes
helium,neon,argon,krypton,xenon,
andradon.
ì  Allthenoblegasesarefoundinsmall
amountsintheearth'satmosphere.
RareEarthElements
(innertransitionmetals)
ì  Thethirtyrareearth
elementsarecomposedof
thelanthanideandac8nide
series.
ì  Mostelementsinthe
ac8nideseriesarecalled
trans-uranium,which
meanssynthe8cormanmade.
ì  Called“theseedsof
technology”
WhatisaTREND?
ì  ATRENDisapredictablechangeinapar8cular
direc8on.
ì  PeriodicTRENDSallowforpredic8onstobemade
aboutchemicalbehavior.
ì  PeriodicTRENDScanberelatedtoatomicstructure
andelectronconfiguraAon.
DiatomicMolecules
ì  Someelementsonlyexistinnatureasdiatomic
molecules:2atomsofthesameelementbonded
together.
ì  Generatesstabilitybysharingelectronstofill
energyhighestlevel.
WhatisPERIODICITY?
ì  Trendsarerecurringinelementalproper8es.
ì  PaEernscanbededucedbyrelaAngelectronconfiguraAonfor
elements–meaning,movingacrossaperiodanddownagroup
intheperiodictable.
ì  ChemicalbehaviorisrelatedtoELECTRONS.
ì  Periodictrendsallowpredic8onstobemadeaboutchemical
behavior.
ì  Describedingenerality–thereARESOMEEXCEPTIONS!
KEYPOINTStoremember!
ì  “like”aEracts“unlike”
ì  protons(+)a#ractelectrons(-)
ì  “like”repels“like”
ì  electrons(-)repelelectrons(-)
KEYPOINTStoremember!
ì  SHIELDINGEFFECT
ì  Whenanatomhasmorethanoneshell,thereisa
DECREASEinaErac8onbetweenthevalence
electronsandthenucleus
ShieldingEffect-EXAMPLE
ì  HydrogenhaselectronsinONLY1SHELL
ì  NOSHIELDING
ì  Lithiumhaselectronsin2SHELLS
ì  Innerelectrons‘shield’thenucleus,offserngsome
oftheprotons’aErac8ontotheelectrons
AtomicRadius
ì  Atomicradius=sizeofanatom
ì  Ionicradius=sizeofanion
ì  Actualatomicradiusisdifficulttodetermine.
ì  Bestrepresenta8onisthedistancebetweenthe
nucleusandtheoutermostelectronshell(valence
shell).
ì  Determinedbytaking½distancebetweentwo
nucleiofcovalentlybondedatoms.
AtomicRadiusPERIODICTREND
ì  Atomicradiusinpm
AtomicRadiusvs.AtomicNumber
ì  Asatomicnumberincreasesacrossaperiod,the
atomicradiusdecreases.
ì  Asprincipleenergylevelincreasesgoingdowna
group,theatomicradiusincreases.
AtomicRadius–What’shappening?
ì  TWOFACTORS:
ì  Nuclearcharge(howmanyprotonsarepresent)
ì  Shieldingeffectofelectronsininnershells
AtomicRadius–What’shappening?
ì  Moreprotonsareaddedmovingacrossaperiod
(atomicnumberincreases)
ì  FillingelectronsinSAMEprincipleenergylevel
ì  STRONGERPULLonelectrons
ATOMICRADIUSDECREASES!
AtomicRadius–What’sHappening?
ì  Movingdownagroup,principleenergylevelincreases.
ì  Moreorbitalsareadded
ì  Electronsinouterorbitalsexperienceshieldingeffect
ì  Electronsarenotpulledinas8ghtlytowardthenucleus
AtomicRadius:
Comparegroupsandperiods
IONIZATIONENERGY–PeriodicTrend
ì  IonizaAonenergyistheamountofenergyrequiredtoremovea
valenceelectronfromtheoutermostshellinanatom.
ì  Losingelectronsformsposi8velychargedionscalledcaAons.
ì  IEisalsoaffectedbynumberofprotonspresentinnucleusand
byelectronshielding.
ì  Energymustbe“putin”toremoveelectrons.
IONIZATIONENERGY-TREND
1stIONIZATIONENERGY
ì  Energyrequiredtoremovethe1stvalenceelectron
IonizationEnergy–What’shappening?
ì  Movingacrossaperiod,numberofprotonsincreases,so
posi8vechargeincreases(GREATERaErac8ontoelectrons!).
ì  SAMEprincipleenergylevel,soNOaddi8onalelectron
shielding
ì  ElectronsareHELDMORESTRONGLYandrequireMORE
ENERGYtoremove
IonizationEnergy–What’shappening?
ì  Movingdownagroup,numberofprotonsincreases,so
posi8vechargeincreases(GREATERaErac8ontoelectrons!).
ì  BUTaddi8onalenergylevelsANDaddi8onalelectron
shielding
ì  ElectronsareHELDLESSSTRONGLYandrequireLESSENERGY
toremove
DegreesofIONIZATIONENERGY
ì  Some8mes,morethanoneelectronwillbe
removedfromanatom.
ì  Eachsuccessiveelectronthatisremovedis
progressivelymoredifficulttoremove,requiring
moreandmoreenergy
ì  WHY?
ì  Fewerelectronsàlessrepulsion
ì  Fewerelectronsàclosertonucleuscausing
strongeraErac8ontoprotons
SuccessiveIonizationEnergies
ElectronAffinity–PeriodicTrend
ì  Electronaffinityisthechangeinenergy,measured
inkJ/mol,foraneutralatomwhengainingan
electron;therela8velikelihoodforgainingan
electron.
ì  Energymaybeaddedorreleased
ì  Gaininganelectronformsanega8velychargedion
calledananion.
Electronaffinity–PeriodicTrend
ì  TWOFACTORS:
ì  Affectedbyatomicstructure(numberofprotons;energy
levels/orbitals).
ì  Affectedbyhowmanyelectronsneededtofulfilloctetrule
forvalenceelectrons(achieveanelectronconfigura8on
sameasitsclosestnoblegas)
ElectronAffinity–PeriodicTrend
ElectronAffinity–What’shappening?
ì  Movingacrossaperiodformaingroupelements,thecloser
theelementistothenoblegasconfigura8on,suchas
elementsingroups15-17,thehighertheelectronaffinity.
ì  Movingacrossaperiod,atomicradiusdecreases,sopull
fromprotonsisgreater.
ElectronAffinity–What’shappening
ì  Movingdownagroupontheperiodictable,energy
levelsincreaseandatomicradiusincreases,causing
less‘pull’onelectronsfromthenucleus
Electronegativity–PeriodicTrend
ì  ElectronegaAvitymeasuresthetendencyofanatomto
aEractabondingpairofelectrons.
ì  TheatomwithGREATERelectronega8vitywillaEractthe
electronsmorestrongly
ì  Createspolarity
2.1
3.0
Differencein
electronegaAvityis0.9
Electronegativity–PeriodicTrend
ì  MeasuredwithPaulingScale
ì  Electronega8vityincreasesacrossaperiod
ì  Electronega8vitydecreasesdownagroup
PeriodicTrends:ALLTOGETHER
ì  Howdoyourememberthetrends?
ì  AtomicradiusistheONLYtrendthathasadifferent
paEern: