a visible suspension in the air of particles of some substance. in other words, a substance in the gaseous state (a gas state) and then distinguished from the liquid or solid state.
Steam
Steam.
I expect you mean iodine vapour. Please see the link.
water vapour
water vapour
Stench.
haze
Water vapour.
humidity
Transpiration
water vapour
If you mean vapour, it is in the gases state of matter.