Air consists of active and inactive components. This was proposed by_____.
A. Mayow in the year $1674$
B. Maeow in the year $1764$
C. Miaw in the year $1864$
D. None of the above

Hint: Air is the mixture of various gases present in the atmosphere. Its components are nitrogen, oxygen, carbon dioxide, inert gases (like argon, neon, xenon), water vapours and impurities like dust particles. All these gases play an important role in sustaining life.

Step-by-Step Solution: John Mayow was a chemist who is famous for his early research into respiration and the nature of air. He proposed that air consists of active and inactive components in the year $1674$ .
Mayow showed through his experiments that combustion happened not by air as a whole but by a more active component present in the air. At that time oxygen was not discovered so he called it nitro-aereus.
He also observed that some materials on burning gained weight instead of losing like antimony which gave him the indication that air was made up of different components some of which are active and some of which are inactive.
He also experimented to prove his argument that this component which was responsible for combustion was also necessary for our life.
Lavoisier was the scientist who named these active and inactive components. This active component is today called oxygen and is important for combustion and respiration. The major inactive component present in the air is nitrogen which actually dilutes the activity of oxygen. Nitrogen is also important as it is essential for growth of plants.

Hence the correct answer is A.

Note: Some facts about main components of air are-
Oxygen is a gas with formula ${O_2}$. It consists of only $21\% $ of the air by volume. It is available in both states in the atmosphere- Free State and combined state. This gas is highly reactive and forms oxides on burning.
Nitrogen is a gas with formula ${N_2}$. It consists of $78.1\% $ of the air by volume. It is produced in nature by the nitrogen fixation process between atmosphere and living organisms.
Carbon dioxide is also a greenhouse gas which has formula $C{O_2}$. It occupies only $0.03\% $ of earth’s atmosphere. It is important for the photosynthesis process of plants.