Page 5 - Curriculum Visions Dynamic Book

nitrogen is called “fixing”. Nature provides two fixing mechanisms. One occurs whenever lightning flashes and heats up the air. Another is through the efforts of the bacteria that live in the nodules of some plant roots (plants called legumes, which include peas, beans and clover). To make use of nitrogen as a fertiliser, people have to dig up rocks containing nitrogen compounds, find chemical ways to make nitrogen compounds or grow legumes in rotation with other plants.
Considerable energy is released when compounds containing nitrogen (N) atoms change and form nitrogen gas (N2). This is why nitrogen compounds are favoured as raw materials for explosives, from gunpowder to nitroglycerine.
Phosphorus
Phosphorus, chemical symbol P, is a solid, first obtained from dried urine! It was soon discovered that phosphorus glowed in the dark and because of this property chemists named the element after the Greek word for “light-bringing”.
Quite unlike nitrogen, phosphorus is very reactive and does not exist on its own in nature. On exposure to air, white phosphorus burns spontaneously. However, like nitrogen, phosphorus is known for its use in weapons, in this case because it produces intense flame. Also like nitrogen, phosphorus is essential to life, its compounds helping in the process of transferring energy within the body.
 Nitrogen dioxide gas being released by a reaction of fuming nitric acid and copper turnings.
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