(From the
Latin Phosphorus, the
morning star Venus) A
paramagnetic non
metallic chemical element, normally a white,
phophorescent, waxy solid, becoming yellow when exposed to
light. It is poisonous and unites easily with
oxygen, so it ignites spontaneously at
room temperature. When heated in sealed tubes it is converted into a red form, which is nonpoisonous and less flammable than the white. When heated under a pressure of 10,000
atmospheres it is converted into a black powder.
Symbol: P
Atomic number: 15
Atomic weight: 30.973761
Density (at room temperature and pressure): 1.82 g/cc (white)
Melting point: 44.15°C
Boiling point: 280°C
Valence: -3, +3, +5
Ground state electron configuration: [Ne]3s23p3
See also: phosphorus-32