The stoma complex regulates the exchange of gases and water vapor between the outside air and the interior of the leaf.

Ice also appears colorless, and water vapor is essentially invisible as a gas.

I will show wonders in the sky above, and signs on the earth beneath blood, and fire, and billows of smoke.

And I will shew wonders in heaven above, and signs in the earth beneath blood, and fire, and vapour of smoke

The gaseous phase of water is known as water vapor (or steam), and is characterized by water assuming the configuration of a transparent cloud.

The flue gas consists of mainly carbon dioxide and water vapour, the latter of which is condensed through cooling.

Metal oxide particles react with a solid, liquid or gaseous fuel in a fluidized bed combustor, producing solid metal particles and a mixture of carbon dioxide and water vapor.

Venera 4 provided the first chemical analysis of the Venusian atmosphere, showing it to be primarily carbon dioxide with a few percent of nitrogen and below one percent of oxygen and water vapors.

For example, methane is oxidized by reaction with naturally occurring hydroxyl radical, OH and degraded to and water vapor ( from the oxidation of methane is not included in the methane Global warming potential).

Its composition depends on what is being burned, but it will usually consist of mostly nitrogen (typically more than two thirds) derived from the combustion air, carbon dioxide (), and water vapor as well as excess oxygen (also derived from the combustion air).

In 1926, by measuring spectral lines that were redshifted by the orbital motions of Mars and Earth, American astronomer Walter Sydney Adams was able to directly measure the amount of oxygen and water vapor in the atmosphere of Mars.