Where does water vapor come from?
Water vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Unlike other forms of water, water vapor is invisible.
Evaporation occurs when a liquid changes into a gas. Most of the water in the air evaporates from the oceans. Water also evaporates from lakes, pond, rivers, puddles, and soil. Winds carry this water vapor all over Earth's surface.
- Humans cannot breathe underwater because our lungs do not have enough surface area to absorb enough oxygen from water, and the lining in our lungs is adapted to handle air rather than water. However, there have been experiments with humans breathing other liquids, like fluorocarbons.
- Water vapor exists as an invisible gas in the air. The amount of water vapor in air varies according to the temperature and density of air. The amount of water vapor ranges from a trace amount up to 4% of the mass of air.
- A measure of the water vapor content of the air is called humidity. It is most often expressed as a ratio of the amount of water vapor present in a given volume (parcel) of air compared to the total amount of water vapor which that same unit of air could actually hold.
Updated: 26th October 2019