nitrogen

• Description
• General information
• Physical data
• Radii
• Electronegativities
• Solid state structure
• Temperatures
• Enthalpies
• Ionization Enthalpies
• Isotopes
• Further information

Description

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.

General information

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#)

Physical data

Standard state: gas at 298 K
Colour: colourless
Density of solid at ambient temperature/kg m^-3: no data
Molar volume/cm³: 13.54

Radii /pm

Atomic: 56
Covalent (single bond):
Pauling radius for the ion [N]^-: 247

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	53.9	52.3	no data	no data

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 3.04
Allred Rochow: 3.07

Crystal Structure

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.

Temperatures (/K)

melting point: 63.05
boiling point: 77.36

Enthalpies /kJ mol^-1

fusion: 0.72
vaporization: 5.58

single bond enthalpies:

N-F	N-Cl	N-Br	N-I	N-N
283	313	no data	no data	945.33

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	1402.3
2nd	2856.1
3rd	4578.1
4th	7475
5th	9440
6th	53266
7th	64359

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
14N	14.003074002 (26)	99.634 (9)
15N	15.00010897 (4)	0.366 (9)

Further Information

• Additional information about WebElements 1.2.2
• This is a licensed copy (here is the full list) of WebElements 1.2.2 and contains a subset of the material contained within the main version of WebElements (version 2)
• For further information please try WebElements version 2
• Sheffield Chemdex: perhaps the largest internet chemistry directory
• Sheffield Chemputer: interactive chemistry calculators on the WWW