Question

if oxygen is78%and nitrogen is21% what will happen

Answer 1

Answer:

Explanation:

The risk of fires would increase a great deal, and this would reduce the amount of oxygen and increase CO2 considerably. This would likely lead to an increased greenhouse effect and greater plant growth. In the long term oxygen concentrations of that degree are unsustainable, and would naturally decrease.

High oxygen environments are very susceptible to fire - look at the crew of Apollo 1. They were in a spaceship on the ground in a sealed 100% oxygen environment, and a small fire very quickly turned into a fireball.

(As an aside: Oxygen is a very reactive gas. Look at benzene for example - benzene is very stable, it rarely reacts with acids, it rarely reacts with bases. Its quite a stable molecule. Put benzene in some oxygen with a small spark and it creates a big enough explosion to power a car. Silver is very unreactive, but it tarnishes in air due to oxygen.)

So the increased oxygen concentration would not be sustainable in the long term. Fires and other oxidation reactions would turn O2 into other forms.