Explanation:

Introduction:
Air is the mixture of gases that surrounds the Earth. It is essential for the survival of all living organisms, including humans. This mixture consists of various gases, such as nitrogen, oxygen, carbon dioxide, and traces of other gases.

Composition of Air:
Air is primarily composed of three main gases: nitrogen, oxygen, and small amounts of other gases. The composition of air is as follows:

- Nitrogen: It constitutes about 78% of the total air volume. Nitrogen is an odorless and colorless gas that is essential for the growth of plants and animals.

- Oxygen: It makes up approximately 21% of the air volume. Oxygen is crucial for the respiration process in living organisms, as it is used to release energy from food.

- Carbon Dioxide: It makes up only about 0.04% of the air volume. Carbon dioxide is a greenhouse gas that plays a vital role in regulating the Earth's temperature.

- Other Gases: Besides nitrogen, oxygen, and carbon dioxide, air also contains traces of gases like argon, neon, helium, methane, and ozone.

Properties of Gases:
Gases have certain characteristics that distinguish them from solids and liquids:

- Gases have no fixed shape or volume. They take the shape and volume of the container they are in.

- Gases are compressible. This means that their volume can be reduced by applying pressure.

- Gases have low density compared to solids and liquids.

- Gases can easily mix with other gases, leading to the homogeneous nature of air.

Air as a Mixture of Gases:
Based on the properties of gases and the composition of air, it is evident that air is a mixture of gases:

- Air does not have a fixed shape or volume. It takes the shape and volume of its container, just like gases.

- Air is a homogeneous mixture, meaning that it has a uniform composition throughout. This is because the gases in air mix thoroughly with each other.

- Air can be separated into its constituent gases through various processes, such as fractional distillation or filtration.

Conclusion:
In conclusion, air is a mixture of gases. It consists of primarily nitrogen, oxygen, carbon dioxide, and traces of other gases. The properties of gases and the composition of air support the fact that air is a mixture of gases.