What is air made up of?

• The air is a mixture of gases.

• The air around us is called the atmosphere.

• The most abundant gas in the air is nitrogen. Air is composed of 78 percent of nitrogen.

• The gas that makes up about one fifth of the air is oxygen because it's 21%.

• The amount of carbon dioxide in the air is a very small number, which is less than one percent.

• If carbon dioxide increases in the atmosphere, it will be a problem.

• There are other gases like argon and methane that exist in small amounts.