its ozone to be truthfully :)
That is ozone.
Nitrogen 78%, oxygen 21%
Because the atmosphere is composed of several different gasses that are fairly uniformly mixed together. The atmosphere is about 78% nitrogen and 21% oxygen with innumerable numbers of other trace gasses.
The air (on ground level, not in a traffic jam!) is composed of ~80% N2, ~20% O2, 0-6% H2O (vary a lot), 0.03% CO2, 1% argon and then traces of other elements. The most abundant element is thus nitrogen N.
Atmosphere
That is ozone.
That is ozone.
That is ozone.
That is ozone.
ozone
Oxygen.
The atmosphere of Europa is composed of only oxygen, which is unusual. It is a very tenuous atmosphere.
No. It is composed mainly of hydrogen and helium. It is about 1% oxygen.
Nitrogen, oxygen, and argon.
oxygen
The atmosphere of the Earth is a gas, not a liquid, and although it does contain oxygen, that is just one part of the atmosphere, which is mostly nitrogen.
Without its oxygen content the Earth's atmosphere would be composed almost entirely of nitrogen and would be chemically inert; oxygen causes the atmosphere to be chemically active (and breathable by humans).