Summary Chem 106 Electron Orbitals Study Guide

Electron Orbitals Study Guide
Introduction to Electron Orbitals
Electron orbitals describe the probable regions where electrons are found around an atomic
nucleus. They are fundamental to understanding atomic structure, chemical bonding, and
quantum mechanics.

Quantum Numbers
Electron orbitals are defined by four quantum numbers:

1. Principal Quantum Number (n)
o Indicates the energy level or shell of the electron.
o Higher n values correspond to higher energy levels and larger orbitals.
o Possible values: n = 1, 2, 3, ...
2. Azimuthal Quantum Number (l)
o Defines the shape of the orbital.
o Values range from 0 to (n-1) for each principal quantum number.
o Corresponding orbital shapes:
 l = 0 → s orbital (spherical)
 l = 1 → p orbital (dumbbell-shaped)
 l = 2 → d orbital (cloverleaf or complex shape)
 l = 3 → f orbital (even more complex shapes)
3. Magnetic Quantum Number (mₗ)
o Specifies the orientation of the orbital in space.
o Values range from -l to +l, including 0.
o Example for p orbitals (l = 1):
 mₗ = -1, 0, +1 (corresponding to px, py, and pz orbitals)
4. Spin Quantum Number (mₛ)
o Defines the spin of the electron within an orbital.
o Possible values: +1/2 or -1/2
o Each orbital can hold a maximum of two electrons with opposite spins.


Types of Electron Orbitals
1. s Orbitals (l = 0)

 Spherical in shape.
 Each energy level has one s orbital (1s, 2s, 3s, etc.).
 Can hold two electrons.

2. p Orbitals (l = 1)