Nitrogen is a Group 15 element. Nitrogen makes up about 78% of the atmosphere by volume. The atmosphere of Mars contains less than 3% nitrogen. Nitrogen can be obtained by liquefaction and fractional distillation from air. 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, and is similar in appearance to water.
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.
Discoveror: Daniel Rutherford
Date discovered: 1772
Discovered at: Scotland
Meaning of name: From the Greek words "nitron genes" meaning "nitre" and "forming" and the Latin word "nitrum" (nitre is a common name for potassium nitrate, KNO#)
Standard state: gas at 298 K
Density of solid at ambient temperature/kg m-3: no data
Molar volume/cm3: 13.54
Covalent (single bond):
Pauling radius for the ion [N]-: 247
Valence shell orbital radius maxima (Rmax)
|radius||53.9||52.3||no data||no data|
Both values are quoted on the Pauling scale.
Allred Rochow: 3.07
structure: hcp (hexagonal close-packed)
The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.
melting point: 63.05
boiling point: 77.36
Enthalpies /kJ mol-1
single bond enthalpies:
Ionization enthalpies /kJ mol-1
This section gives some data for naturally occurring isotopes.
||% natural abundance
|14N||14.003074002 (26)||99.634 (9)|
|15N||15.00010897 (4)||0.366 (9)|