Phosphorus (P)

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.

Atomic Number

15

Atomic Mass

30.974 u

Category

nonmetal

Phase

solid

Density

1.82 g/cm³

Electron Shells

2, 8, 5

Atomic Structure

Protons: 15 • Electrons: 15 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p³

Discovery

1669 • Hennig Brand