Chapter4,Section4.2:OrganizingtheElements

HowdidMendeleevdiscoverthepatternthatledtotheperiodictable?

Howaretheelementsorganizedinthemodernperiodictable?

Section4.2:LearningObjectives

Describehowtheelementsareorganizedinthemodernperiodictable:includingtheorder,theregions,family/groups,andperiods.

7a.Studentsknowhowtoidentifyregionscorrespondingtometals,nonmetals,andinertgases

• apk

• PeriodicTableofElements Isorganizedlikeacalendarby• Columns androws

• columns (familygroups)• rows (periods)• location,location,location,predictstheelement’s properties

EightBasicFamilyGroups

SevenPeriods

• Russianscientistinthe19th century.

• In1836,developedthefirstP.T.ofElementswithjust63elements.

• Noticedarepeatingpatternofpropertiesintheelementsandgroupedthembysimilarities.

DmitriMendeleev

•Recordedtheproperties(bothphysicalandchemical)oftheelementsoncards.•Arrangedtheelementsbyrepeatingpropertiesandbyincreasingmass(fromlightesttoheaviest),amistakehedidnotknowyet.•“periodic”meansarepeatingpattern.

DmitriMendeleev

•HewasabletousehisP.T.topredictcorrectlythepropertiesandmassofthemissingelementsyettobediscovered.

TheModernPeriodicTableorElements• TheTableisdividedintotwomainpartsbythezig-zag

line,andsub-dividedintothreeclasses.1. Metalsontheleft,2.Nonmetalsontheright,3.Rare

EarthMetalsonthebottomofthechart.• Onespecialgroupalongthezig-zag line:Metalloids

(Semimetals)

FollowtheProtons,They’rethePros• ThePTisarrangedbythenumberofPROTONS.• Theprotonsarethe“Pro’s”,they’retheboss.• Startingwiththeatomthathasonlyoneproton,

HYDROGEN• Hydrogenhasoneproton,oneelectron,andNO

neutrons.•thePTcontainsmorethan100elements.•Arrangedinorderof increasingAtomicNumber,startingwith#1,Hydrogen.

• Hydrogen,#1,thelightest,withoneproton,(and1electron)andatomicmassof1.(noneutrons)

• Helium,#2,withtwoprotons,(and2electrons)andatomicmassof4.(with2neutrons)

FindingDataonElements• Eachsquareintheperiodictablelistsfourpiecesofinformation:anelement’satomicnumber,chemicalsymbol,name,andatomicmass.

• 17• F• Cl• Br• I• At

• EachGroup isafamilynamedvertically.

• NamedbycolumnNumberortopelementinthegroup,or

• aspecialname.• elementshavesimilarpropertieslikefamilymembers withsameBondingPowerbyValenceelectrons

18BasicFamilyGroups

•

• Period(horizontalrow)• Aperiodtellsthenumberofenergylevels(shells,rings)

• membershavesameenergylevel,butdifferentproperties.

7periods(rows)

DrawthisatominNB1. Howmanyprotonsare

inthisatom?2. Howmanyelectrons

areinthisatom?3. Howmanyenergy

levelsareshowninthisatom?

4. Inwhatperiodisthisatom?

5. HowmanyenergylevelsareinPeriod5?

• EveryFamilyGroup hasthesameBondingPower inachemicalreaction.

• Chemicalbondingisdonebyspecialelectrons withthe highestenergycalledValenceElectrons

• VE’sarelocatedontheoutsidering,farthestlevelfromthenucleus,thehighestenergylevel.

• EachFamilyGrouphasthesamenumberofVE’s.

• Forexample,everymemberoftheCarbonfamilyhas4valenceelectrons.

BondingPower– ValenceElectrons

4valenceelectronsonthecarbonatom

• NumberofvalenceelectronsforeachgroupmatchestheGroupnumber.

• Forexample:Group1hasoneVE• Group2has2VE’s• (SkipovertoGroup13tofollowthe

pattern)• Group13has3VE’s.• Group14has4VE’s.• Group15,5VE’s.• Group16,6VE’s• Group17,7VE’s• Group18,8VE’s,(exceptHe,2VE’s)

BondingPower– ValenceElectrons

Quick Quiz: 6 questions. (with answers)• How many electrons? 7 (total)• How many VEs? 5 (on outside ring)• Which period? 2 (2 rings/energy levels)• Which group? 15 (5 VE’s)• What is the Atomic Number? 7 (Period 2, Group 15)• What is the name of this element? Nitrogen

Cfu Observethediagramofthisatomicmodel.

Quick Quiz: 7 questions.• How many electrons?• How many VEs?• Which period?• Which group?• What is the Atomic Number?• What is the name of this element?• Pb is in the same family, compare their sizes, who’s larger? Why?

Cfu Observethediagramofthisatomicmodel.

ElementsRaphttps://www.youtube.com/watch?v=cAnOUwPfHlk

Elements– TheyMightbyGiantshttps://www.youtube.com/watch?v=Uy0m7jnyv6U

Elements– TomLehrerhttps://www.youtube.com/watch?v=zGM-wSKFBpo

IfyouwishtowatchthesethreevideosonElements,copyandpastetheYouTubelinksintoyourbrowser.

EndofSection4.2:OrganizingtheElements

HowdidMendeleevdiscoverthepatternthatledtotheperiodictable?

Howaretheelementsorganizedinthemodernperiodictable?