1. Electrons in Atoms - continued
Chapter 5
5.1 Light and Quantized Energy
5.2 Quantum Theory and the Atom
5.3 Electron Configurations

2. Atomic Orbitals Describe the location of electrons
Orbital = region of space
Principle quantum # (n) = energy level
n = 1, 2, 3, 4, 5 …
with increasing distance from the nucleus
Energy Sublevels = s, p, d, f (see p )
s sphere 1 orbital max 2 electrons
p dumbbell 3 (x, y, z) 6
d clover leaf f
Max 2 electrons in each orbital

4. Order of filling orbitals (p.135)

5. Pauli Exclusion Principle: Hund’s Rule:
Aufbau Principle:
Electrons enter orbitals of lowest energy first
Pauli Exclusion Principle:
Atomic orbital can have at most 2 electrons
Hund’s Rule:
For orbitals of equal energy, 1 electron enters each orbital until all orbitals have 1 electron with parallel spins

6. Electron Configuration and Orbital NotationSi Ni Ar B
Cr and Cu (exceptions)
Al, Ge, Sb, Po

7. Link s, p, d, f orbitals to blocks in periodic table
Noble gas shorthand notation for electron configuration
Valence electrons = number of electrons in the highest energy level
Electron dot (Lewis) structure