Which gas dominates in atmosphere by volume?

The volume of carbon dioxide in atmosphere is

The volume of water vapour in the atmosphere is

………… layer is characterised by uniformity in composition of gases.

Lowermost layer of the atmosphere is

………… layer is free from clouds.

In which layer conditions are most ideal for flying jet aircrafts?

…………….. layer contains ozone layer.

……….. layer consists of electrically charged ions.

…………… is the highest layer in the atmosphere.