Electron Configurations and Orbital Diagrams

Maximum Number of Electrons In Each Sublevel Maximum Number of Electrons In Each Sublevel Maximum Number SublevelNumber of Orbitals of Electrons s 1 2 p 3 6 d 5 10 f 7 14 LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World, 1996, page 146

General Rules Aufbau Principle –Electrons fill the lowest energy orbitals first. –“Lazy Tenant Rule” Courtesy Christy Johannesson 2s2s 3s3s 4s4s 5s5s 6s6s 7s7s 1s1s 2p2p 3p3p 4p4p 5p5p 6p6p 3d3d 4d4d 5d5d 6d6d 4f4f 5f5f 1s1s 2s2s 2p2p 3s3s 3p3p 4s4s 4p4p 3d3d 4d4d 5s5s 5p5p 6s6s 7s7s 6p6p 6d6d 4f4f 5f5f 5d5d Energy

Order in which subshells are filled with electrons 1s2s3s4s5s6s7s1s2s3s4s5s6s7s 2p3p4p5p6p 2p3p4p5p6p 3d4d5d6d 3d4d5d6d 4f5f 4f5f 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d …

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

Orbital Diagrams

General Rules Pauli Exclusion PrinciplePauli Exclusion Principle –Each orbital can hold TWO electrons with opposite spins. Courtesy Christy Johannesson Wolfgang Pauli

RIGHT WRONG General Rules Hund’s RuleHund’s Rule –Within a sublevel, place one electron per orbital before pairing them. –“Empty Bus Seat Rule” Courtesy Christy Johannesson

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”

O 8e - Orbital Diagram Electron Configuration 1s 2 1s 2 2s 2 2s 2 2p 4 Notation 1s 2s 2p Courtesy Christy Johannesson O

Orbital Filling Element 1s 2s 2p x 2p y 2p z 3s Configuration Orbital Filling Element 1s 2s 2p x 2p y 2p z 3s Configuration Electron Configurations Electron H He Li C N O F Ne Na 1s 1 1s 2 2s 2 2p 6 3s 1 1s 2 2s 2 2p 6 1s 2 2s 2 2p 5 1s 2 2s 2 2p 4 1s 2 2s 2 2p 3 1s 2 2s 2 2p 2 1s 2 2s 1 1s 2 NOT CORRECT Violates Hund’s Rule Electron Configurations Electron H He Li C N O F Ne Na 1s 1 1s 2 2s 2 2p 6 3s 1 1s 2 2s 2 2p 6 1s 2 2s 2 2p 5 1s 2 2s 2 2p 4 1s 2 2s 2 2p 3 1s 2 2s 2 2p 2 1s 2 2s 1 1s 2

Orbital Filling Element 1s 2s 2p x 2p y 2p z 3s Configuration Electron Configurations Electron H He Li C N O F Ne Na 1s 1 1s 2 2s 2 2p 6 3s 1 1s 2 2s 2 2p 6 1s 2 2s 2 2p 5 1s 2 2s 2 2p 4 1s 2 2s 2 2p 3 1s 2 2s 2 2p 2 1s 2 2s 1 1s 2

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 LaHeLiCNAlArFFe

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 LaHeLiCNAlArFFe

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 LaLiCNAlArFFe

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 LaHeCNAlArFFe

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 LaHeLiNAlArFFe

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 LaHeLiCAlArFFe

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 LaHeLiCNAlArFe

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 LaHeLiCNArFFe

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 LaHeLiCNAlFFe

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 LaHeLiCNAlArF 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 LaHeLiCNF Bohr Model Lanthanum Electron Configuration

s p d (n-1) f (n-2) 6767 Periodic Patterns 1s1s1s1s 2s2s2s2s 3s3s3s3s 4s4s4s4s 5s5s5s5s 6s6s6s6s 7s7s7s7s 3d3d3d3d 4d4d4d4d 5d5d5d5d 6d6d6d6d 1s1s1s1s 2p2p2p2p 3p3p3p3p 4p4p4p4p 5p5p5p5p 6p6p6p6p 7p7p7p7p 4f4f4f4f 5f5f5f5f

Period # –energy level (subtract for d & f) A/B Group # –total # of valence e - Column within sublevel block –# of e - in sublevel Courtesy Christy Johannesson

s-block1st Period 1s 1 1 st column of s-block Periodic Patterns Example - Hydrogen Courtesy Christy Johannesson

Full energy level Full sublevel (s, p, d, f) Half-full sublevel Stability Courtesy Christy Johannesson

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