Question

why does air contain less oxygen at high altitude? ​

Answer 1

It is because there are fewer molecules of everything present, including oxygen. So although the percentage of oxygen in the atmosphere is the same, the thinner air means there is less oxygen to breathe. Try using our barometric pressure calculator to see how air pressure changes at high altitudes.

Answer 2

In air oxygen is in the less quantity because temperature is. high then the particles of oxygen gas is less in the air