Phosphorus is a nonmetal solid that comes in three forms: black, white and red. White phosphorus can spontaneously ignite and is poisonous. The element has an atomic weight of 31 and atomic number of 15, and its atomic symbol is P.
Henry Brand was the first to isolated pure phosphorus. In 1669, Brand processed 60 buckets of urine to isolate phosphorus in its pure form. In order to protect white phosphorus from air, it is stored underwater. Red phosphorus is the result of heated white phosphorus, and is an ingredient in pesticides, matches and fireworks. Black phosphorus, which has no known practical use, comes from heated white phosphorus with a mercury catalyst.