Quantum Numbers and Electron Configurations

Key ideas about quantum numbers and electron configurations.

Quantum Number “n”

The principal quantum number, that measures energy level.

Quantum number “I”

The angular momentum quantum number, it indicates orbital shape. It can take values from 0 to (n-1), corresponding to s, p, d, and f orbitals.

l = 0

S orbitals

l = 1

P orbitals

l = 2

D orbitals

l = 3

F orbitals

Quantum number ml

The magnetic quantum number that indicates orientation of the orbital. It ranges from -l to l.

Number of orbitals

The amount of possible m_l numbers

Exception to the configuration rule

Where the expected electron configuration is different than expected, and occurs next to the half filled d orbitals on the periodic table and next to the full filled d orbitals.