Quantum Number Calculator

Calculate all possible quantum numbers for electrons in atomic orbitals and shells

Calculate Quantum Numbers

Main energy shell (1-7). Determines electron energy level and distance from nucleus.

Quantum Number Results

n = 1
Principal
K Shell
1
Total Orbitals
n² orbitals
2
Max Electrons
2n² electrons

Subshells in Shell n = 1:

1sl = 0
Orbitals: 1
Max e⁻: 2
mₗ: 0
mₛ: ±½

All Quantum Number Combinations

nlmₗmₛOrbital
100+1/21s
100-1/21s

Four Quantum Numbers

n

Principal (n)

Energy level, shell

1, 2, 3, 4, ...

l

Angular (l)

Orbital shape, subshell

0 to n-1 (s,p,d,f,...)

mₗ

Magnetic (mₗ)

Orbital orientation

-l to +l

mₛ

Spin (mₛ)

Electron spin direction

+½ or -½

Orbital Types

sl = 0
Spherical, 1 orbital
pl = 1
Dumbbell, 3 orbitals
dl = 2
Cloverleaf, 5 orbitals
fl = 3
Complex, 7 orbitals

Quantum Rules

Each electron has unique quantum numbers (Pauli exclusion)

Maximum 2 electrons per orbital (opposite spins)

n² total orbitals in shell n

2n² maximum electrons in shell n

Understanding Quantum Numbers

What are Quantum Numbers?

Quantum numbers are a set of four numbers that completely describe an electron in an atom. They serve as the "address" of each electron, specifying its energy, orbital shape, orientation, and spin direction. No two electrons can have identical quantum numbers (Pauli exclusion principle).

Why are They Important?

  • Predict electron configuration and chemical properties
  • Explain atomic structure and bonding
  • Understand periodic table organization
  • Describe electron behavior in atoms

Quantum Number Relationships

n: 1, 2, 3, 4, ... (energy levels)

l: 0 to (n-1) (subshells)

mₗ: -l to +l (orbital orientations)

mₛ: +½ or -½ (spin directions)

Angular Momentum

Orbital: L = √[l(l+1)] ℏ

Spin: S = √[s(s+1)] ℏ = (√3/2) ℏ

where ℏ = h/2π = 1.055 × 10⁻³⁴ J⋅s

Electron Capacity Examples

⚛️ Shell n=1 (K)

Subshells: 1s

Orbitals: 1 (1²)

Max electrons: 2 (2×1²)

First and smallest shell

⚛️ Shell n=2 (L)

Subshells: 2s, 2p

Orbitals: 4 (2²)

Max electrons: 8 (2×2²)

Contains s and p orbitals

⚛️ Shell n=3 (M)

Subshells: 3s, 3p, 3d

Orbitals: 9 (3²)

Max electrons: 18 (2×3²)

First shell with d orbitals