Why does the amount of oxygen in the air not change when temperature changes?

Question

desperate to know! please :)

Answer 1

This question does not make sense. I think you have some false information or a bad idea about how things work.
I'll try to explain:

The amount of oxygen DOES change for a certain volume of air with temperature change...but so does the amount of all the other gases that are in our atmosphere. When you heat gases up they expand...which means they take up space.Try it for yourself: Blow up a balloon then put the balloon in the freezer. The balloon will be smaller. The amount of molecules of "air" is still the same in the balloon, but now they are closer together and taking up less space. Next, take that same balloon outside if it is warm out. You will notice after a while that the balloon is now bigger. Same amount of "stuff" in the balloon...just now it is taking up more space.

When gases are heated, their molecules become excited. They move around faster because there is more energy (heat). Since they move faster, they take up more space. That is the general principle behind it. So, the PERCENTAGE of oxygen does not change, but the amount does in a specific volume, except for our balloon experiment because the gas was trapped and couldn't escape.

Answer 2

if the oxygen is already there, it won't leave just because the temperature goes down. However, if you are referring to high altitudes, it is not that there is less oxygen, it is that the air is less thick as a whole, making it harder for humans accustomed to living in the thicker atmosphere at lower heights to get enoough oxygen in one breath.

Answer 3

It does...
Percentage does not change but amount goes down
as air warms & becomes lighter...