Question

what is the percentage proportion of oxygen in air? why is Oxygen called active air?​

Answer 1

Answer:

(b) 20.9%, oxygen is called active air because it supports life on earth. It is essential for the process of combustion

Answer 2

Answer:

The percentage proportion of oxygen in air 21%.

Oxygen is called active air because it supports life and combustion. Oxygen is essential for respiration because the body uses it to 'burn' food molecules. Animals take in oxygen when inhaling and give off carbon dioxide when exhaling.