Nitrogen cycle

Everything in this whole world is made out of atoms and molecules. Atoms and molecules are so small that you cannot see them. Another oxygen, represented by the letter O. When 1 nitrogen atom combines with 2 oxygen atoms they form a molecule called NO2. The name of NO2 is actually called nitrogen dioxide. Nitrogen dioxide combines with other toxic gases, the brown haze is called smog. 

Airborne Nitrogen

Nitrogen is one of the 90 elements, or pure substances that exists on the planet Earth. About 78% of our air sis made out of N2. Nitrogen's other name is called inert gas. Nitrogen atoms don't react with other atoms. Here's a fact, light bulbs actually contain nitrogen (N2).

Nitrogen Compounded 

Because that nitrogen atoms don't really bond with other atoms, not many nitrogen exist naturally on Earth. Protein molecules in animals and plants contain nitrogen. Protein is part of all our cells and bones even more. A small amount of compounds called nitrous oxide gas (N2O) exists naturally in our atmosphere. A compound called sodium nitrate (NaNO3) or Chile saltpeter, is found underground in South America, liquid nitrogen is so cold if you put a berry in liquid nitrogen it will freeze. 

The Nitrogen cycle

Every living thing is also part of the nitrogen cycle. Here is the cycle of nitrogen. Nitrogen travels from the air to soil  to plants and to animals, and back to the soil and air.