The Foundations of Chemistry

OCCURRENCE OF NITROGEN

Nitrogen, N 2 , is a colorless, odorless, tasteless gas that makes up about 75% by mass and

78% by volume of the atmosphere. Nitrogen compounds form only a minor portion of

the earth’s crust, but all living matter contains nitrogen. The primary natural inorganic

deposits of nitrogen are very localized. They consist mostly of KNO 3 and NaNO 3. Most

sodium nitrate is mined in Chile.

24-13

958 CHAPTER 24: Some Nonmetals and Metalloids

TABLE 24-8 Oxidation States of Nitrogen and Examples

 3  2  10 
 1 
 2 
 3 
 4 
 5

NH 3 N 2 H 4 NH 2 OH N 2 N 2 ONON 2 O 3 NO 2 N 2 O 5
ammonia hydrazine hydroxylamine nitrogen dinitrogen nitrogen dinitrogen nitrogen dinitrogen
oxide oxide trioxide dioxide pentoxide

NH 4
NH 2 Cl H 2 N 2 O 2 HNO 2 N 2 O 4 HNO 3
ammonium chloramine hyponitrous nitrous dinitrogen nitric acid
ion acid acid tetroxide
NH 2  NO 2  NO 3 
amide ion nitrite ion nitrate ion

Every protein contains nitrogen in
each of its fundamental amino acid
units.

Industrial

fixation

Via electrical

storms and

rain

Atmospheric nitrogen

Nitrogen fixation

by cyanobacteria

Denitrifying bacteria

in anaerobic mud

Urea

Decomposers

Amino acids

Ammonia

Nitrogen-fixing

bacteria in roots

and soil

NO 3  and NH 4 


in soil water

Amino acid

synthesis

Runoff

from

land

A schematic representation of the nitrogen cycle.