Phosphorus
Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but due to its high reactivity, phosphorus is never found as a free element on Earth. Instead phosphorus-containing minerals are almost always present in their maximally oxidised state, as inorganic phosphate rocks.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
10 is the [Ne] core total across two shells.
At a glance
- Atomic number
- 15
- Atomic mass
- 30.973762 u
- Phase
- Solid
- Density
- 1.823 g/cm³
- Melting point
- Unavailable
- Boiling point
- Unavailable
- First ionization energy
- 1,011.8 kJ/mol
- Electronegativity
- 2.19
- Electron affinity
- 72.037 kJ/mol
- Molar heat capacity
- 23.824 J/(mol·K)
- Period
- 3
- Appearance
- colourless, waxy white, yellow, scarlet, red, violet, black
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.