Phosphorus (P)
[Ne] 3s² 3p³. 3 unpaired electrons, period 3, group 15, p block.
Element or ion
Type a symbol, a name or an atomic number, add a charge such as Fe3+ or Cl-, or tap an element in the table. Orbitals fill from m = −l up, spin +½ first.
PPhosphorus, Z = 15, 30.974 u
[Ne] 3s2 3p3
In full: 1s² 2s² 2p⁶ 3s² 3p³
- Blockp block
- Period3
- Group15
- Valence5
- Unpaired3
- MagneticPara
Last electron 3p
- n3shell
- l1p subshell
- m+1orbital
- s+½spin up
Step by step
- Phosphorus has 15 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p³.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p³.
- Replace the neon core with [Ne]: [Ne] 3s² 3p³.
Phosphorus (P): the numbers
| Atomic number | 15 |
|---|---|
| Atomic mass | 30.974 u |
| Period | 3 |
| Group | 15 |
| Block | p block |
| Valence electrons | 5 |
| Unpaired electrons | 3 |
| Magnetic | paramagnetic |
| Last electron | 3p: n = 3, l = 1, m = +1, s = +1/2 |
Phosphorus (P): quick answers
What is the electronic configuration of phosphorus?
Phosphorus has 15 electrons: 1s² 2s² 2p⁶ 3s² 3p³, or [Ne] 3s² 3p³ in short.
How many unpaired electrons does phosphorus have?
Phosphorus has 3 unpaired electrons, so it is paramagnetic. Put one electron in each box of a subshell before pairing (Hund’s rule) to see them.
What are the quantum numbers of the last electron of phosphorus?
The last electron goes into 3p: n = 3, l = 1, m = +1, s = +1/2. Orbitals fill from m = −l up, spin +½ first.