Question

The presence of $\_\_\_\_\_\_$ in air controls the process of burning

Answer 1

Hint: The presence of nitrogen in air controls the process of burning. Nitrogen is a colorless, odorless and tasteless gas that makes up $78\% $ of the air we breathe. It is nonflammable and it will not support combustion. It is commonly thought of and used as an inert gas but it is not truly inert.

Complete answer:
Any combustion at high temperatures in atmospheric air, which is $78\% $ percent nitrogen, will also create small amounts of several nitrogen oxides, commonly referred to as $NOx$, since the combustion of nitrogen is thermodynamically favored at high, but not low temperatures.
During air fuel combustion, the chemically inert nitrogen in the air dilutes the reactive oxygen and carries away some of the energy in the hot combustion exhaust gas. An increase in oxygen in the combustion air can reduce the energy loss in the exhaust gases and increase heating system efficiency.
Nitrogen operates as a fire suppressant by reducing the oxygen content within a room to a point at which the fire will extinguish, without compromising the safety of individuals present in the room. Nitrogen will not decompose or produce any byproducts when exposed to a flame.

Note:
Nitrogen is an inert gas meaning it doesn't chemically react with other gases and it isn't toxic. But breathing pure nitrogen is deadly. That's because the gas displaces oxygen in the lungs. Unconsciousness can occur within one or two breaths, according to the Chemical Safety and Hazard Investigation Board.