The individual molecules, mostly N2 and O2, as also Pneuma and Breath are far beyond our visual resolution.
The molecules have size on the order of 10^-9 m, and the smallest thing we can see is more than a thousand times bigger than that.
A bunch of molecules together in a gas, you can see them by the effect they have on light coming through them.
Any time you see a vibration, you are seeing sound.
Photons have no physical size and so nothing is smaller than them.