All living things, such as humans, animals, and plants, need oxygen in the air to survive. Oxygen is a colorless, tasteless, and odorless gas which is a component of air. Oxygen forms about 21 percent of the Earth's atmosphere. Without air and the oxygen gas, the Earth would not have any living organisms. Because air is essential to our survival, our bodies are constantly interacting with it.
Air can enter our bodies through our mouths and noses.
Inhalation is the process of breathing air through the mouth and nose into our lungs. Once air has entered the lungs, cells take the oxygen from the air and distribute it throughout the body. Once the cells have finished with the oxygen, our body exhales and pushes out the remaining air from our lungs as carbon dioxide . Air is necessary in many activities. Air is working when things, such as leaves and branches and clouds, are moving.