Atomic Number:	7
Atomic Symbol:	N
Atomic Weight:	14.00674
Electron Configuration:	[He]2s22p3

Nitrogen is a Group 15 element. Nitrogen makes up about 78% of the atmosphere by volume but the atmosphere of  Mars contains less than 3% nitrogen. The element seemed so inert that Lavoisier named it azote, meaning "without  life". However, its compounds are vital components of foods, fertilizers, and explosives. Nitrogen gas is colourless,
odourless, and generally inert. As a liquid it is also colourless
and odourless.

When nitrogen is heated, it combines directly with magnesium, lithium, or calcium. When mixed with oxygen and subjected to electric sparks, it forms nitric oxide (NO) and then the dioxide (NO2). When heated under pressure with hydrogen in the presence of a suitable catalyst , ammonia forms (Haber process). Nitrogen is "fixed" from the atmosphere by bacteria in the roots of certain plants such as
  clover. Hence the usefulness of clover in crop rotation.

Here is a brief summary of the isolation of nitrogen. There is never any need ot make nitrogen in the laboratory as it is readily available commercially or through in-house air liquefaction plants. However the decomposition of sodium azide is one route to N2 and decomposition is ammonium dichromate is another. Both reactions must only be carried out under controlled conditions by a professional.

NaN3 (300°C)  2Na + 3N2

(NH4)2Cr2O7  N2 + Cr2O3 + 4H2O

Nitrogen is made on massive scale by liquefaction of air and fractional distillation of the resulting liquid air to separate out oxygen and other gases. Very high purity nitrogen is available by this route.

March 27, 2008