Nitrogen electron configuration (ground state)
The nitrogen electron configuration describes how the electrons of a neutral nitrogen atom are distributed among orbitals in the lowest-energy (ground) state. Nitrogen has atomic number \(Z=7\), meaning 7 protons and (for a neutral atom) 7 electrons.
Step 1: Use atomic number to get total electrons
For a neutral atom, the electron count equals the atomic number: \[ n_e = Z = 7 \]
Step 2: Fill orbitals in aufbau order
The aufbau principle fills lower-energy orbitals first. For the first two shells relevant to nitrogen, the order is: 1s → 2s → 2p.
| Subshell | Max electrons | Electrons placed (nitrogen) | Running total |
|---|---|---|---|
| 1s | 2 | 2 | 2 |
| 2s | 2 | 2 | 4 |
| 2p | 6 | 3 | 7 |
After filling 1s and 2s, \(7 - 4 = 3\) electrons remain, so they go into the 2p subshell: 2p3.
Step 3: Apply Pauli exclusion and Hund’s rule (orbital diagram meaning)
- Pauli exclusion principle: an orbital holds at most 2 electrons, and if 2 are present they must have opposite spins.
- Hund’s rule: in a set of equal-energy orbitals (the three 2p orbitals), electrons occupy them singly with parallel spins before pairing.
Visualization: nitrogen orbital diagram for 1s2 2s2 2p3
Useful interpretations for general chemistry
Nitrogen is in period 2 and group 15. Its valence-shell configuration is 2s2 2p3, so it has 5 valence electrons and commonly forms three covalent bonds (with one lone pair) in many neutral molecules.
Answer
The nitrogen electron configuration for a neutral nitrogen atom is 1s2 2s2 2p3 (or [He] 2s2 2p3), and the orbital diagram shows paired electrons in 1s and 2s plus three unpaired electrons distributed one per 2p orbital.