Though we know air is essential for breathing, but have we ever given it a serious thought? Have you wondered what is it that makes the air so important and why is it important to preserve the environment? What effect will it have on our health if we allow air pollution to grow? What is the composition of air? Let us know more.
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Composition of Air
We often take air as a single unit. In reality, 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.
It is also important to understand that the composition stated above is the ideal composition of air, which maintains the fine balance in nature. In places where this composition of air varies, the atmospheric balance of nature may be tilted. For instance, in an industrial area, the composition of air can differ drastically. There may be a high quantity of harmful gases emitted from the industrial chimneys that can increase the amount of carbon-dioxide in the air, making it harmful to anyone who breathes such air.
Let us now look at the components in the composition of air separately.
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Learn more about Water here in detail.
Oxygen
The most important gas in the composition is oxygen. Oxygen is an important gas, both for humans as well as the atmosphere. It supports in breathing for living beings, but at the same time, oxygen is a combustible gas, which means, it can catch fire quickly. Thus, when you light a candle, it easily lights up. Try doing the same in a vacuum, and you will not be able to light it. Which means air consists of combustible substance too. This is why the composition of oxygen in the air is just about 21%. Just enough to give us healthy lungs, but not enough to start a random fire!
Learn more about Oxygen in detail here.
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.
Argon
Presence of Argon in the air was first suspected by Henry Cavendish in 1785, but it was not confirmed until 1894 when Lord Rayleigh and Sir William Ramsay attested to it. This gas is known to occur naturally in the environment and easily dissipates in a well-ventilated space. In itself, argon is an asphyxiant and inhalation of it can lead to dizziness and nausea in a person.
Carbon dioxide
Carbon dioxide is infused in the air due to respiration. Living beings inhale oxygen and exhale carbon dioxide. There are other ways by which carbon dioxide is infused in the atmosphere, and its composition keeps changing depending on the place where you are. In general, it should occupy about 0.38% of the earth’s total atmosphere.
Water vapor
Finally, we have water vapor. When the water present in the water bodies evaporates due to heat, it rises up and mixes into the atmosphere. You can assess the presence of water vapor in the air by measuring the humidity level. You will notice that as we come closer to sea, the level of humidity rises. This is because the amount of water vapor is more near seaside areas.
Other Particles
Apart from the natural gases, air also contains things like smoke and dust. The closer you are to the city, the amount of these particles in the air increases.
Simple activity for you
Activity: How can you prove that air supports burning?
What to do?
Take a candle and try to burn it in air. Take another candle and try to burn it while keeping it submerged in water. You will observe that, while the candle burns in air; it does not burn in water. This simple activity shows that air support burning. This simple activity can be done by you at home and is a great help in understanding this property of the air around us.
You may have seen rural women blowing air while lighting up the chulha. Blowing air helps in quickly burning the wood in the chulha. This is also a proof to help you understand that the air around us does support burning.
Question For You
Q. In desert areas, water vapor content is :
a. Different       b. Higher
c. Low           d. Constant
Sol:Â c. Low
In the desert areas, the water vapor content is significantly lower than the regular areas. This is because the deserts are mainly hot areas as there is lack of water and if there is lack of water than there is lack of water vapor also in the air.
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