Phosphorus is the second element in Group 15 of the periodic table. The elements in this group are sometimes referred to as the nitrogen family of elements. Phosphorus has an atomic number of 15, an atomic mass of 30.97376, and a chemical symbol of P.

Properties

Phosphorus exists in three allotropic forms, named after their colors: white (or yellow) phosphorus; red phosphorus; and black (or violet) phosphorus. White phosphorus is a waxy, transparent solid with a melting point of 111°F (44.1°C), a boiling point of 536°F (280°C), and a density of 1.88 grams per cubic centimeter. If kept in a vacuum, white phosphorus sublimes if exposed to light. White phosphorus is also phosphorescent, giving off a beautiful greenish white glow. It does not dissolve in water, although it does dissolve in many organic liquids, such as benzene, chloroform, and carbon disulfide. White phosphorus sometimes appears slightly yellowish because...