Heisenberg Uncertainty Principle: imposs. to know both p (momentum) of e- and its location in space simultaneously

Quantum Mechanics

Schrodinger’s wave eq.: includes wave & particle behavior of e- (see handout)

Method to determine probability region of e- around nucleus

Quantum Numbers:

n	principle Q.N. (Energy level) 1,2,3,…
l	Azimuthal Q.N.(sublevel) 0, 1, 2, …(n-1) 0 = s sublevel 1 = p 2 = d 3 = f
ml	Magnetic Q.N. (orbital, orientation in space) - l ….+ l (2l +1) Tot # orbitals in E level = n^2 Tot # e- in E level = 2 n^2
ms	Electron spin Q.N. + ½ or – ½ (↑↓) oppositely directed magnetic field orientations

Pauli Exclusion princ.: no 2 e- can have same 4 Q.N. (orbital can hold 2e- with opposite spins)

Aufbau Princ.: e- fill orbitals in order of increasing E

Hund’s Rule: lowest E is attained when e- have same spin in degenerate orbitals (Bus Seat Rule)

degenerate orbitals: orbitals w/in same sublevel, have equal E

Effective Nuclear Charge

e- around nucleus

§ attracted to nucleus

§ repelled by ea. other

e- of outer E levels not as attracted to nucleus as inner E level e-

(Shielding/screening effect)

Effective Nuclear charge: net positive charge attracting e- to nucleus

Z_eff = Z – S

Z = atomic number (# p⁺)

S = avg. # e- between nucleus & e- of concern

*e- repulsion causes dif E values of s, p, d, f sublevels

e- configurations

arrangement of e- around nucleus

Valence: outer E level e-

Core: e- in inner E levels