Question

A note on Air or atmosphere.

Answer 1

Air is important for living things. People need to breathe, and so do lots of other animals—and plants! Breathing is part of a process called respiration. During respiration, a living thing takes in oxygen from the air and gives out carbon dioxide.

Not only is oxygen present in air required for combustion – the process that allows fires to form, and as a result powers most fuel-burning generators, machines and vehicles – but air can be used to create power directly. Wind, when passed through a large turbine, can be used to generate electricity.

Answer 2

The atmosphere is the layer of gases around the Earth. It is held in place by Earth's gravity. It is made up mainly of nitrogen (78.1%). It also has plentiful oxygen (20.9%) and small amounts of argon (0.9%), carbon dioxide (~ 0.035%), water vapor, and other gases. The atmosphere protects life on Earth by absorbing (taking) ultraviolet rays from the sun. It makes our days cooler and our nights warmer.

Solid particulates, including ash, dust, volcanic ash, etc. are small parts of atmosphere. They are important in making clouds and fog.

The atmosphere does not end at a specific place. The higher above the Earth something is, the thinner the atmosphere around it is. There is no clear border between the atmosphere and outer space. 75% of the atmosphere is within 11 kilometres (6.8 miles) of the Earth's surface.