Saying 氣 "Qi" means simply "air" is a too simple of a translation of the word, too colloquial, too childish even. When you see "air" they don't mean it the same way as "air" of the five elements, that's an entirely different word, which is 空 - Kong. Even 空氣 Kong Qi means "atmosphere", rather than simply air.
When used in conjunction with "Qi", the literal word for air is more correct as being: 氣態 - Q́ Tài.
"Gas" is just a valid of a literal translation for the character "Qi", perhaps more so than "air".
"Qi" is more correctly translated as "Vital Breath", which as far as I have ever read the ancient classics was used to mean "essence".
They mean it as the inner "vapors', "spirit', "humors" (of ancient western alchemy and early medicine), "life force", "intrinsic energy".
There are plenty of natural processes that don't involve air that would pertain to "qi". For example, there are plenty of anaerobic bacteria and virus and so on that don't involve air at all. But, clearly viruses have "Qi", even very disruptive Qi. A fetus inside the womb is not breathing air (absorbing oxygen, but not literally 'air", from the mother's bloodstream, but a fetus is considered to be the atom bomb of Qi.
With air, there must be oxygen, but with there doesn't have to be oxygen for Qi to exist in many type of natural things.
Even the non-Chinese concepts that are similar to "Qi" from other cultures refer to the "soul", the "internal forces" than actual "air".
Is there air at the atomic level? at the sub-atomic level? at the quantum level?
No, but there is Qi at these levels.
Clearly, energy is the more accurate way to translate what is meant by "Qi".