Name       : Phosphorus
Symbol     : P
Atomic #   : 15
Atom weight: 30.9738
Melting P. : 44.1
Boiling P. : 280
Oxidation  : +3, -3, +5
Pronounced : FOS-fer-es
From       : Greek phosphoros, "bringer of light"
Identified : Hennig Brand in 1669
Appearance : The most common white form is a waxy, phosphorescent solid
Note       : This element is noted for its ability to grow in the dark

[Properties]

  Phosphorus belongs to the nitrogen group, Group VA, on the periodic table
of the elements. It is a nonmetal, or metalloid, having properties closer to
those of Sulfur (S) and arsenic (As) than to silicon (Si) and nitrogen in
the same portion of the table.
  Phosphorus has ten known allotropic forms. This is an unusually large
number of allotropes for any element, but the picture can be greatly
simplified by placing each of them into one of three general categories:
white, red, and black phosphorus.
  White phorphorus is a white, waxy substance that usually takes on a
slightly yellow tinge due to the presence of impurities. There are two major
allotropic forms of white phosphorus. The alpha form has a subic crystalline
structure and is stable down to -78 degrees where it turns into the beta
form. The beta form is somewhat more dense and has a hexagonal crystalline
structure.
  Red phosphorus is formed by exposing white phosphorus to sunlight or
heating it at about 250 degrees. Black phosphorus is also produced by
heating white phosphorus, but in the presence of a mercury catalyst and seed
crystal of black phosphorus.
  White phosphorus is by far the most volatile and explosive of the three
basic allotropic forms. It is also the msot useful in the production of
other compounds of phosphorus. Red phosphorus is, itself, a fairly stable
form, but the heat from the simple friction is enough to convert it to
explosive white phosphorus. This feature is used to great advantage in the
manufacture of safely matches. Black phosphorus is the least reaction and
has the least commercial value.