All living things are constantly searching for nitrogen in a form their bodies can use. Nitrogen makes up an important part of the bodies of humans, plants, and animals. Nitrogen is a necessary part of the protein substance which is man’s body-building material. Without this substance, no one could grow or repair damaged or worn-out tissues.
Nitrogen makes up 78 percent of the air we breathe, while oxygen is only 21 percent. There are about 20,000,000 tonnes of nitrogen above every square mile of the earth’s surface.
It is a colorless, odorless, tasteless gas that dissolves only slightly in water. When extreme cold or pressure is applied, it changes to a liquid. The temperature at which it becomes a liquid is — 218 degrees Centigrade. It would seem easy for living things to get the nitrogen they need since it is all around them in the air. But in nature, only a few plants are known as “legumes” are able to use pure nitrogen from the air. Human bodies cannot use pure nitrogen. We get the nitrogen we need by taking in proteins. These proteins are obtained by eating certain plants or plant-eating animals.
We breathe in nitrogen but do not use it in our lungs. We simply breathe it out again unchanged. What the nitrogen does is dilute the oxygen of the air so that we do not get too much at one time.
Nitrogen is useful only when combined with other chemicals to form compounds. It is chemically inactive and does not combine easily with other elements.
What Is Nitrogen Used For?
Nitrogen is important to the chemical industry. It is used to make fertilizers, nitric acid, nylon, dyes, and explosives. To make these products, nitrogen must first be reacted with hydrogen to produce ammonia.