3.1 THE PERIODIC LAW. The Periodic Table. The known elements. Page 3-1. Chapter 3: ELECTRONIC STRUCTURE and THE PERIODIC LAW

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1 Chapte : ELECTRONC STRUCTURE and TE PERODC LAW Using the Peiodic Table, locate and classify common elements Detemine the numbe of electons in an element s valence shell Relate electonic stuctue and chemical popeties to location in the Peiodic Table. TE PERODC LAW D. Mendeleev (869): Chemical popeties of of elements vay in in a peiodic (egula) way Elements with simila popeties occu at at egula intevals This concept helps us undestand and pedict PYSCAL PROPERTES CEMCAL PROPERTES CEMCAL REACTONS The Peiodic Table Column: GROUP o family The Peiodic Table: Elements in Pope Positions Li Be Na Mg 4 Ca Sc 5 Rb S Y Row: PEROD VB VB V V Cu Ti V C Mn e Co Ni Ru Rh Pd Ag Z Nb Mo Tc Os Pt Au f Ta W Re VA VA Al Si P g V V e Se B Te Xe L B i e N M a g C S a c R S Y b C B L C P s a a e N P S E G T D E d m m u d b y o T Y m b L u T i Z f C M C V n e o N M T R R b o c u h T W R O a e s O A S C P S l i l N C Z G G A S B i u n a e s e P A C S S T d g d n n b e P A T P B P A t u g l b i o t e N e A X e R n Ra Ac R a A T P c h a N P U p u A C B m m k C f E s M N L m d o Dy o E Md No L nfomation in the Peiodic Table The known elements ~ ELEMENTS ARE CURRENTLY CONRMED: 4 Silve Ag 0.9 Atomic numbe Name of the element Elemental Symbol Atomic mass (weight) 9 ae metals 0 ae adioactive 0 ae man-made (all adioactive) occu as gases occu as liquids (at 5 C) Page -

2 .-.4 ELECTRONC ARRANGEMENTS in ATOMS N. Boh (9): Electons have cetain specific (QUANTZED) enegies Electons occupy ORBTS o SELLS specific distances fom the nucleus Electons change obits by absobing o eleasing enegy ORBT ORBTo o SELL SELL Enegy Absoption: electon jumps to to highe enegy level + Enegy Emission: electon falls to to lowe enegy level, enegy lost as as light o o heat Pincipal Enegy Levels View the atom as being an onion-like seies of layes Each laye can hold only a cetain numbe of electons As we move out, the layes get lage and can hold moe electons A new laye is added fo each ow o peiod in the Peiodic Table (although electons ae not necessaily being added o emoved fom the outemost shell) Peiod Peiod Peiod Each enegy level can only hold just so many electons: N max max = n whee n = numbe of of shell BUT: Shells ae filled one SUBSELL at a time. Each subshell contains ORBTALS holding a maximum numbe of electons. Outemost Shell N max 8 8 Outemost Shell Numbe of Subshells Numbe of Obitals N total + 6 = = 8 Page -

3 Atomic Obitals d Electons occupy ORBTALS (electon wave functions) n = 4s s p Each obital descibes a specific spatial distibution of electon density Enegy n = s p Each obital has a chaacteistic enegy and shape n = s 90% pob. s obital NCREASNG ENERGY s s NOTE: These obitals ae degeneate, they have the same enegy p z node s node p x p y n = 4s p d s Enegy n = s p d xz d z + othes n = s Page -

4 nne vs. Valence Electons VALENCE ELECTRONS This is whee most chemical eactions occu Electon Configuations o the non-tansition elements (except e): Nº O VALENCE ELECTRONS = GROUP Nº Goup has e - Goup V has e - etc... NNER ELECTRONS Not much happens hee unde nomal conditions VALENCE ENERGY LEVEL (SELL) = PEROD Nº Peiod has valence e - in shell Peiod has valence e - in shell etc... Only one goup has all its subshells completely filled: Goup The Noble (fomely, net) Gases ELEMENT ATOMC Nº e Ne 0 A 8 6 Xe 54 Noble gas configuations ELECTRONS / SELL Atoms will gain, lose, o o shae electons to to achieve a noble gas configuation.5-.6 The Peiodic Table and Tends in Element Popeties s s s s s s 4 4s 5 5s 6 6s s s VB VB V V d 4d 5d 6d 6d 4f 4f 5f 5f VA VA V V p p p p 4p 4p 5p 5p 6p 6p s s Li Na Be Mg Ca Deceasing atomic size nceasing ease of gaining electons Al Si P Se B nceasing atomic size nceasing ease of losing electons e Page -4

5 CLASSYNG TE ELEMENTS ELEMENTS N TE SAME GROUP AVE SMLAR VALENCE-SELL ELECTRON CONGURATONS Since chemical behavio involves valence-shell electons, ELEMENTS N TE SAME GROUP AVE SMLAR CEMCAL PROPERTES Metals and Nonmetals METALS lustous, malleable and ductile conductos usually solid at 5 C lose electons NONMETALS physical state vaies at 5 C non-conductos many exist as diatomic molecules (O, etc) gain electons METALLODS both metal and nonmetal popeties NONMETALS: Atoms often gain electons Li Be Na Mg 4 Ca Sc 5 Rb S Y VB VB V Ti V C Z Nb Mo f Ta W V Mn Tc Re e Ru Os Metalloids Co Ni Cu Rh Pd Ag M e t a l l s Pt Au g VA VA Al Si P V V e Nonmetals Se B Te Xe Moe Metallic VB VB V V Moe Metallic Moe Nonmetallic VA VA V V Moe Nonmetallic Ra Ac Dy o E Md No L METALS: Atoms lose electons Common Goup Names Alkali Metals Li Be Na Mg 4 Ca Sc 5 Rb S Y Ra Ac Alkaline Eath Metals VB VB V V Ti V C Mn Z Nb Mo Tc f Ta W Re e Co Ni Cu Ru Rh Pd Ag Os Pt Au Tansition Metals Noble Gases alogens g VA VA Al Si P V V e Se B Te Xe Common elements that exist as diatomic molecules (X ) at oom tempeatue: Li Be Mg Na Ca Sc Rb S Y Cs Ba La Ra Ac VB VB V Ti V C Z Nb Mo f Ta W V M n Tc Re e Ru Os Co Ni Cu Rh Pd Ag Pt Au g B Al Ga n Tl VA C Si Ge Sn Pb VA N P As Sb Bi V O S Se Te Po V Cl Cl B B At e Ne A Xe Rn Dy o E Md No L Page -5

6 Li Be Na Mg VB VB V V Liquids VA VA Al Si P V V e O S Cl Ne Gases A Li Na Be Mg Radioactive Elements VB VB V V VA VA Al Si P V V e 4 Ca Sc Ti V C Mn e Co Ni Cu Se B 4 Ca Sc Ti V C Mn e Co Ni Cu Se B 5 Rb S Y Z Nb Mo Tc S o l l i i d s f Ta W Re Ru Rh Pd Ag Os Pt Au g Te Po At Xe Rn 5 6 Rb Cs S Ba Y La Z f Nb Ta Mo W Tc Re Ru Os Rh Pd Ag Pt Au g Te Xe Ra Ac Ra Ac Dy o E Dy o E Md No L Md No L Page -6