Name the major gas present in the:
(a) inhaled air

(b) exhaled air

Hint: In the given question we will discuss the two gases when we inhale air inside and when we exhale air outside of the body. Meanwhile our body consumes it or we can say inhale the gas and exhale the gas so this gaseous exchange occurs by diffusion in the alveoli in the lungs.

Complete step-by-step answer :
> Breathing process is an essential fragment of the respiratory system, it is a complex process where air travels inside and outside of the lungs. Thought the Respiration process is an exercise which causes muscles to expand and compress along with the release of energy in the form of glucose.
> So, when we Inhale air it contains more oxygen which is further used to create energy and less carbon dioxide than the Exhaled air which contains more carbon dioxide which is produced as a waste product of energy production though the less oxygen as it has been used in the respiration process.
> As we know that the Gaseous exchange occurs by diffusion which occurs in the alveoli within the lungs.  As a result of it, the composition of inhaled and exhaled air is dissimilar.

Hence, the major gas present in the (a) inhaled air is oxygen (b) exhaled air is carbon dioxide.

Note: The principal function of the respiratory system is to take inside oxygen gas and eradicate carbon dioxide gas. Oxygen passes rapidly through the air-blood barrier within the blood in the capillaries. Similarly, carbon dioxide passes from the blood into the alveoli and then exhales.