1. most unreactive gas next to inert gases. 2. largely present in the atmosphere [78%; oxygen is only 47%] 3. one of the most important element for life [amino acid, DNA/RNA] well, you can take a short look at wikipedia... http://en.wikipedia.org/wiki/Nitrogen

"Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere." "At atmospheric pressure molecular nitrogen condenses (liquifies) at 77 K (−195.8 °C) and freezes at 63 K (−210.0 °C) into the beta hexagonal close-packed crystal allotropic form. Below 35.4 K (−237.6 °C) nitrogen assumes the alpha cubic crystal allotropic form. Liquid nitrogen, a fluid resembling water in appearance, but with 80.8% of the density (the density of liquid nitrogen at its boiling point is 0.808 g/mL), is a common cryogen." "Molecular nitrogen (14N2) is largely transparent to infrared and visible radiation because it is a homonuclear molecule and thus has no dipole moment to couple to electromagnetic radiation at these wavelengths. Significant absorption occurs at extreme ultraviolet wavelengths, beginning around 100 nanometers. This is associated with electronic transitions in the molecule to states in which charge is not distributed evenly between nitrogen atoms. Nitrogen absorption leads to significant absorption of ultraviolet radiation in the Earth's upper atmosphere as well as in the atmospheres of other planetary bodies. For similar reasons, pure molecular nitrogen lasers typically emit light in the ultraviolet range. Nitrogen also makes a contribution to visible air glow from the Earth's upper atmosphere, through electron impact excitation followed by emission. This visible blue air glow (seen in the polar aurora and in the re-entry glow of returning spacecraft) typically results not from molecular nitrogen, but rather from free nitrogen atoms combining with oxygen to form nitric oxide (NO)." Source and further information: http://en.wikipedia.org/wiki/Nitrogen "Physical properties of Nitrogen: Boiling Point at 1atm: -195.8° Freezing Point at 1atm: -209.9° Density of the gas at 21.1° and 1atm: 1.153 kg/m3" Source and further information: http://www.praxair.com/praxair.nsf/0/cdda20a87d5647a485256afc002c46b8?OpenDocument "Nitrogen (N2) is a colorless, odorless and tasteless gas that makes up 78.09% (by volume) of the air we breathe. It is nonflammable and it will not support combustion. Nitrogen gas is slightly lighter than air and slightly soluble in water. [...] Gaseous nitrogen is valued for inertness. It is used to shield potentially reactive materials from contact with oxygen. Liquid nitrogen is valued for coldness as well as inertness. When liquid nitrogen is vaporized and warmed to ambient temperature, it absorbs a large quantity of heat. The combination of inertness and its intensely cold initial state makes liquid nitrogen an ideal coolant for certain applications such as food freezing. Liquid nitrogen is also used to cool materials which are heat sensitive or normally soft to allow machining or fracturing. Examples are used tires, plastics, certain metals and even pharmaceuticals." Source and further information: http://www.uigi.com/nitrogen.html (this page contains also a table with some properties of nitrogen, with metric units and imperial units)

See thus link :- http://en.wikipedia.org/wiki/Nitrogen thus may help too http://periodic.lanl.gov/elements/7.html