Supplemental Guide: Notes On Quantum Numbers

Symbol

Name

Meaning

Possible Values

Connection to Electron Configuration or Orbital Diagram

n

Principle Quantum Number

Energy Level  or “shell” (how far the electron is from the nucleus)

n= 1, 2, 3 …∞

(whole numbers from 1 to infinity)

the ‘2’ in 2p⁶

l

Angular Momentum Quantum Number

Shape of the Orbital (what type of subshell)

l= 0, …(n-1)

(whole numbers from 0 to “n-1”)

If l=0; s-orbital

If l=1; p-orbital

If l=2; d-orbital, etc.

m_l

Magnetic Quantum Number

Orientation in space (which specific orbital the electron is in)

m_l = - l , …0, … l

(integers from negative ‘l’ to positive ‘l’)

tells which orbital the electron occupies

m_s

Spin Quantum Number

the spin of the electron (clockwise or counter clockwise)

m_s= +1/2 or -1/2

which direction the arrow points in orbital diagrams (Arrows symbolize electrons)