Phosphorus (P)
Phosphorus is element 15, a reactive nonmetal in period 3, group 15 of the periodic table. At room temperature it is a solid.
Electron configuration [Ne] 3s2 3p3
Electrons per shell 2, 8, 5
Phosphorus data
| Atomic number | 15 |
|---|---|
| Symbol | P |
| Atomic mass | 30.974 u |
| Category | Reactive nonmetal |
| Group | 15 |
| Period | 3 |
| Block | p |
| State at 25 °C | solid |
| Melting point | 317 K (43.9 °C) |
| Boiling point | 554 K (280.9 °C) |
| Density | 1.823 g/cm³ |
| Electronegativity (Pauling) | 2.19 |
| Atomic radius | 106 pm |
| 1st ionization energy | 1012 kJ/mol |
| Electron affinity | -72 kJ/mol |
| Oxidation states | -3, -2, -1, +1, +2, +3, +4, +5 |
| Common ion charge | 3− |
| Discovered | 1669 |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through phosphorus’s configuration and its ions →
Where phosphorus sits
Phosphorus belongs to the reactive nonmetals. Its Pauling electronegativity of 2.19 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.
Phosphorus FAQ
What is the electron configuration of phosphorus?
Phosphorus (Z = 15) has the configuration 1s2 2s2 2p6 3s2 3p3. In noble-gas shorthand that is [Ne] 3s2 3p3.
How many valence electrons does phosphorus have?
5 (outer shell (n = 3)).
What is the atomic mass of phosphorus?
The standard atomic weight of phosphorus is 30.974 u, so one mole weighs 30.974 g.
Is phosphorus a metal?
No. Phosphorus is a reactive nonmetal.
What is the charge of a phosphorus ion?
Phosphorus most commonly forms P3−.