Electron Configuration Filling-Order of Electrons in an Atom

4f4f 4d4d 4p4p 4s4s n = 4 3d3d 3p3p 3s3s n = 3 2p2p 2s2s n = 2 1s1s n = 1 Energy Sublevels

4f4f 4d4d 4p4p 4s4s n = 4 3d3d 3p3p 3s3s n = 3 2p2p 2s2s n = 2 1s1s n = 1 Energy Sublevels s s s s p p p d df 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 …

Filling Rules for Electron Orbitals Aufbau Principle: Electrons are added one at a time to the lowest energy orbitals available until all the electrons of the atom have been accounted for. Pauli Exclusion Principle: An orbital can hold a maximum of two electrons. To occupy the same orbital, two electrons must spin in opposite directions. Hund’s Rule: Electrons occupy equal-energy orbitals so that a maximum number of unpaired electrons results. *Aufbau is German for “building up”

Energy Level Diagram of a Many-Electron Atom Arbitrary Energy Scale s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles  1982, page 177

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Bohr Model Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N HH He Li C N Al Ar F Fe LaHeLiCNAlArFFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Bohr Model Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N H = 1s 1 Hydrogen H He Li C N Al Ar F Fe LaHeLiCNAlArFFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Bohr Model Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N He = 1s 2 Helium HH He Li C N Al Ar F Fe LaLiCNAlArFFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Bohr Model Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N Li = 1s 2 2s 1 Lithium HH He Li C N Al Ar F Fe LaHeCNAlArFFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Bohr Model Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N C = 1s 2 2s 2 2p 2 Carbon HH He Li C N Al Ar F Fe LaHeLiNAlArFFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N N = 1s 2 2s 2 2p 3 Bohr Model Nitrogen Hund’s Rule “maximum number of unpaired orbitals”. HH He Li C N Al Ar F Fe LaHeLiCAlArFFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Bohr Model Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N F = 1s 2 2s 2 2p 5 Fluorine HH He Li C N Al Ar F Fe LaHeLiCNAlArFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Bohr Model Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N Al = 1s 2 2s 2 2p 6 3s 2 3p 1 Aluminum HH He Li C N Al Ar F Fe LaHeLiCNArFFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS Electron Configuration CLICK ON ELEMENT TO FILL IN CHARTS N Ar = 1s 2 2s 2 2p 6 3s 2 3p 6 Bohr Model Argon HH He Li C N Al Ar F Fe LaHeLiCNAlFFeLa

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS CLICK ON ELEMENT TO FILL IN CHARTS Fe = 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 6 N HH He Li C N Al Ar F Fe LaHeLiCNAlArFLa Bohr Model Iron Electron Configuration

Energy Level Diagram Arbitrary Energy Scale 1s 2s 2p 3s 3p 4s 4p 3d 5s 5p 4d 6s 6p 5d 4f NUCLEUS CLICK ON ELEMENT TO FILL IN CHARTS La = 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 5d 1 N HH He Li C N Al Ar F Fe LaHeLiCNAlArFFe Bohr Model Lanthanum Electron Configuration

Shorthand Configuration

Orbital Diagrams for Nickel 2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s 2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s Excited State Pauli Exclusion Hund’s Rule Ni

Orbital Diagrams for Nickel 2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s 2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s Excited State VIOLATES Pauli Exclusion VIOLATES Hund’s Rule Ni

Write out the complete electron configuration for the following: 1) An atom of nitrogen 2) An atom of silver 3) An atom of uranium (shorthand) Fill in the orbital boxes for an atom of nickel (Ni) 2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s Which rule states no two electrons can spin the same direction in a single orbital? Extra credit: Draw a Bohr model of a Ti 4+ cation. Ti 4+ is isoelectronic to Argon. POP QUIZ

Write out the complete electron configuration for the following: 1) An atom of nitrogen 2) An atom of silver 3) An atom of uranium (shorthand) Fill in the orbital boxes for an atom of nickel (Ni) 2s2s2p2p 3s3s 3p3p4s4s3d3d1s1s Which rule states no two electrons can spin the same direction in a single orbital? 1s 2 2s 2 2p 3 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 9 [Rn]7s 2 6d 1 5f 3 Extra credit: Draw a Bohr model of a Ti 4+ cation. 22+ n = n Pauli exclusion principle Ti 4+ is isoelectronic to Argon. Answer Key

Periodic Table – Filling Order

Electron Configurations and the Periodic Table

Orbitals Being Filled 1s1s 2s2s 3s3s 4s4s 5s5s 6s6s 7s7s 3d3d 4d4d 5d5d 6d6d 2p2p 3p3p 4p4p 5p5p 6p6p 1s1s La Ac f4f 5f5f Lanthanide series Actinide series Groups 8 Periods

Electron Filling in Periodic Table s d p s f    

Li 3 H1H1 He 2 C6C6 N7N7 O8O8 F9F9 Ne 10 Na 11 B5B5 Be 4 H1H1 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 Cs 55 Ba 56 Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 Fr 87 Ra 88 Rf 104 Db 105 Sg 106 Bh 107 Hs 108 Mt 109 Mg 12 Ce 58 Pr 59 Nd 60 Pm 61 Sm 62 Eu 63 Gd 64 Tb 65 Dy 66 Ho 67 Er 68 Tm 69 Yb 70 Lu 71 Th 90 Pa 91 U 92 Np 93 Pu 94 Am 95 Cm 96 Bk 97 Cf 98 Es 99 Fm 100 Md 101 No 102 Lr 103 La 57 Ac s d p s f    

s d p s f     Electron Filling in Periodic Table Li 2s 1 H 1s 1 He 1s 2 C 2p 2 N 2p 3 O 2p 4 F 2p 5 Ne 2p 6 Na 3s 1 B 2p 1 Be 2s 2 H 1s 1 Al 3p 1 Si 3p 2 P 3p 3 S 3p 4 Cl 3p 5 Ar 3p 6 K 4s 1 Ca 4s 2 Sc 3d 1 Ti 3d 2 V 3d 3 Cr 3d 5 Mn 3d 5 Fe 3d 6 Co 3d 7 Ni 3d 8 Cu 3d 10 Zn 3d 10 Ga 4p 1 Ge 4p 2 As 4p 3 Se 4p 4 Br 4p 5 Kr 4p 6 Rb 5s 1 Sr 5s 2 Y 4d 1 Zr 4d 2 Nb 4d 4 Mo 4d 5 Tc 4d 6 Ru 4d 7 Rh 4d 8 Pd 4d 10 Ag 4d 10 Cd 4p 1 In 5p 1 Sn 5p 2 Sb 5p 3 Te 5p 4 I 5p 5 Xe 5p 6 Cs 6s 1 Ba 6s 2 Hf 5d 2 Ta 5d 3 W 5d 4 Re 5d 5 Os 5d 6 Ir 5d 7 Pt 5d 9 Au 5d 10 Hg 5d 10 Tl 6p 1 Pb 6p 2 Bi 6p 3 Po 6p 4 At 6p 5 Rn 6p 6 Fr 7s 1 Ra 7s 2 H 1s 1 H 1s 1 H 1s 1 H 1s 1 H 1s 1 H 1s 1 Mg 3s 2 Ce 4f 2 Pr 4f 3 Nd 4f 4 Pm 4f 5 Sm 4f 6 Eu 4f 7 Gd 4f 7 Tb 4f 9 Dy 4f 10 Ho 4f 11 Er 4f 12 Tm 4f 13 Yb 4f 14 Lu 4f 114 Th 6d 2 Pa 5f 2 U 5f 3 Np 5f 4 Pu 5f 6 Am 5f 7 Cm 5f 7 Bk 5f 8 Cf 5f 10 Es 5f 11 Fm 5f 14 Md 5f 13 No 5f 14 Lr 5f 14 La 5d 1 Ac 6d s d p s f    

Electron Filling in Periodic Table K4s1K4s1 Ca 4s 2 Sc 3d 1 Ti 3d 2 V3d3V3d3 Mn 3d 5 Fe 3d 6 Co 3d 7 Ni 3d 8 Cr 3d 4 Cu 3d 9 Zn 3d 10 Ga 4p 1 Ge 4p 2 As 4p 3 Se 4p 4 Br 4p 5 Kr 4p s d p s Cr 4s 1 3d 5 Cu 4s 1 3d 10 4f4f 4d4d 4p4p 4s4s n = 4 3d3d 3p3p 3s3s n = 3 2p2p 2s2s n = 2 1s1sn = 1 Energy 4s3d Cr 4s 1 3d 5 4s3d Cu 4s 1 3d 10 Cr 3d 5 Cu 3d 10

Electron Dot Diagrams H Li Na K Be Mg Ca B Al Ga C Si Ge N P As O S Se F Cl Br Ne Ar Kr He Group 1A 2A 3A 4A 5A 6A 7A 8A = valence electron s1s1 s2s2 s2p2s2p2 s2p3s2p3 s2p4s2p4 s2p5s2p5 s2p6s2p6 s2p1s2p1

First Four Energy Levels n = 1 n = 2 n = 3 n = 4 Energy

Sublevels

Principal Level 2 Divided

4f4f 4d4d 4p4p 4s4s n = 4 3d3d 3p3p 3s3s n = 3 2p2p 2s2s n = 2 1s1s n = 1 Energy Sublevels

Metals, Nonmetals, Metalloids

Periodic Table