Phosphorus

Phosphorus is a non-metal that belongs to the group 15 of the periodic table. The element exists in several forms. The most abundant of those two forms are white and red phosphorus. White phosphorus glows in the dark and is inflammable above temperature of 30C and is a deadly poison.
==History==
Phosphorus was first made by Hennig Brandt in Hamburg in Germany in 1669. Brandt evaporated urine and heated the residue until it turned red hot. The glowing hot vapour was condensed with application of water. For several years, phosphorus was manufactured in the aforementioned manner. People discovered that bone was made of Calcium Phosphate which was a great source of Phosphorus. Bone is dissolved in sulphuric acid to form phosphoric acid. The phosphoric acid is then heated with charcoal to form white phosphorus. The latter process proved feasible for the market and led to its increased availability in the market.
==Appearance==
The two main forms of phosphorus are white phosphorus and red phosphorus. White phosphorus is a poisonous, waxy solid and contact with skin can cause severe burns. White phosphorous glows in the dark and is flammable when exposed to air. 
Red phosphorus is an amorphous non-toxic solid.
==Uses==
White phosphorus is used in flares and incendiary devices. Red phosphorus is used to make the side-patches of matchboxes and used in safety matches.
Phosphorus is widely used in fertilisers. Ammonium phosphate is made from phosphate ores. The ores are first converted into phosphoric acids before being made into ammonium phosphate.
==Biology==
Phosphorus forms the sugar-phosphate backbone of DNA and RNA. It is important for energy transfer in cells as part of ATP (adenosine triphosphate), and is found in many other biologically important molecules. Bones are made of calcium phosphate. Overuse of feritilisers containing phosphoruus can cause them to pollute rivers and cause algae to grow rapidly. The algae block light in water which blocks photosynthesis. Oxygen dissolved in water soon gets used up and the lake dies.
Category:Element