Question

nitrogen and oxygen are called permanent gases of the atmosphere​

Answer 1

Answer:

nitrogen 70% and oxygen 18%

Answer 2

Answer:

Nitrogen and oxygen are called permanent gases because they form the major portion of our atmosphere.

Explanation:

Our atmosphere is made up of different kinds of gases. These gases are found in a free state or in combined form, but there is a mixture of different types of gases that are found in the atmosphere. Along with all these gases, the highest percentage of gases are nitrogen and oxygen.

Nitrogen is about 78% of total air present in the atmosphere and oxygen forms the second highest 21% of total gases present in the atmosphere the rest are different gases like Argon, Carbon dioxide, water vapour, etc. Since they form such a large portion of the atmosphere that is more than half of it that's why they are called permanent gases.