Calculadora de Configuración ElectrónicaFórmula

Electron Configuration

How It Works

Electrons fill orbitals following three rules: 1. Aufbau Principle: Fill lowest energy orbitals first (1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, ...) 2. Pauli Exclusion: Each orbital holds at most 2 electrons with opposite spins 3. Hund's Rule: Within a subshell, one electron goes in each orbital before pairing

The order of filling follows the diagonal rule or is memorized from periodic table blocks.

Ejemplo Resuelto

Find the electron configuration of sodium (Z = 11).

  1. Z = 11, so 11 electrons to place
  2. 1s² (2 electrons, 9 remaining)
  3. 2s² (2 electrons, 7 remaining)
  4. 2p⁶ (6 electrons, 1 remaining)
  5. 3s¹ (1 electron, 0 remaining)
  6. Configuration: 1s² 2s² 2p⁶ 3s¹
  7. Noble gas notation: [Ne] 3s¹
  8. Valence electrons: 1