At standard conditions, nitrogen is found in a gaseous state. As a chemical element, it can be found in each of the known material states, including solid, liquid, gas, and plasma. However, to be found in these other states requires special conditions. The temperatures and pressures found in the everyday world yield raw nitrogen in a gaseous state. As a chemical compound, nitrogen can be found in the other states. For example, it is a key component in both ammonia and gunpowder.
What Is a Gas?
Chemists define a gas as the state of matter between plasma and liquid. This state is often characterized by a relatively small quantity of atoms in a large volume. The gaseous state is very loose, giving atoms a lot of room to move around. Gas and liquid both obey the physical rules of fluid dynamics. However, a liquid is much easier to perceive than a gas, which is often invisible and intangible.
What Are Standard Conditions?
The quality known as “standard conditions” is defined by a specific temperature and pressure. Although various institutions devise their own specific figures, the most widely accepted come from two organizations: The International Union of Pure and Applied Chemistry and the National Institutes of Standards and Technology. These groups set forth standard conditions as zero degrees Celsius and 14.5 pounds per square inch of pressure.
Nitrogen: All around Us
Diatomic nitrogen is a key component in the atmosphere you breathe. Though you may assume you are inhaling oxygen and exhaling carbon dioxide, in fact the atmosphere is a much more complex mixture. Nitrogen comprises over 78% of the atmosphere.
A Cold Liquid and a Colder Solid
Nitrogen gas can be cooled to form both liquid and solid states. However, the temperatures required for this to occur are incredibly low. Liquid nitrogen boils at -195.79 degrees Celsius. Solid nitrogen melts at -210 degrees Celsius. A temperature both lower than the boiling point and higher than the melting point will yield liquid nitrogen. Temperatures lower than the melting point will yield solid nitrogen.
McNaught, Alan D., and Andrew Wilkinson
Compendium of Chemical Terminology: IUPAC Recommendations
2nd ed. Oxford [England: Blackwell Science, 1997. Print.
Los Alamos National Laboratory
Periodic Table of Elements: Nitrogen
Periodic Table of the Elements
States of Matter