The air is composed of several gases, The composition of air consists of three key components of air, namely Nitrogen (78%), Oxygen (21%), Argon (1%), Carbon-di-oxide (0.03%), and water vapor. Air also has some other gases but they are in very minute percentage.
Components of Air
- Water vapor: We know that water present in oceans and rivers evaporates during summer and escapes into the air. Thus water vapor is one of the components of the air. It occupies a very less percentage of the earth’s atmosphere.
- Oxygen: Oxygen is an important gas, both for humans as well as the atmosphere. It supports breathing for living beings, but at the same time, oxygen is a combustible gas, which means, it can catch fire quickly. Have you ever tried to burn a candle in absence of air? If you would try you would notice that it doesn’t burn in absence of air. Air contains some matter which supports combustion. This substance is oxygen. Oxygen is one of the major components of the air around us. Air comprises almost 21% oxygen.
- Nitrogen: To balance out oxygen, there is Nitrogen. It is a non-combustible gas and occupies the highest percentage of air. This is why, when you blow on a candle it is easily extinguished. This is done because of the presence of nitrogen. Nitrogen is also one of the most abundantly found gases on earth. It occupies nearly 78% of the earth’s atmosphere and is the most abundant gas on our planet.
- Carbon dioxide: Carbon dioxide is mainly produced due to respiration by plants and animals or the burning of fuel. It occupies 0.038% of the earth’s atmosphere. Its occupancy keeps on changing from one place to another in our atmosphere.
- Smoke and dust particles: Smoke is present in our atmosphere due to the burning of fuels. Its occupancy varies from place to place. It is a mixture of gases and is often harmful. Apart from these, dust particles are also present in our atmosphere which we observe when we see a ray of light in a dark room. Smoke and dust particles occupy less than 1% of the earth’s atmosphere.
Properties of Air
- Colorless and odorless: Air generally has no color or odor. It is an invisible matter that can only be felt. All living things breathe air for their survival. Moving air is called wind.
- Occupy space: It is a mixture of different gases. Hence, like every other matter, they also occupy space. On blowing, a balloon expands because the air being blown into it fills up space.
- Air exerts pressure: It has weight, and the pressure exerted by the weight of air is known as air pressure. Due to gravity, this mixture of gases near the surface is denser than at high altitudes. This is why the gaseous atmosphere in the mountains is thinner than that at the surface.
- Expansion: Another property is its expanding property. On heating, it expands and occupies more space. The more it expands, the thinner it becomes. Hence, the pressure of the warm wind is lower than that of the cold wind.