When the supply of water vapor and of atmospheric carbon dioxide is small, an extreme type of climate usually prevails.
Crystals of frost puffed out as the water vapor left the air.
As long as the actual amount of water vapor in the air is less than that which the air can hold, no rain falls.
This water vapor changes into droplets of water when it gets cool enough.
On top of that, this original earth mass, composed of molten rock and gases and water vapor, was condensing.
When we say that water evaporates, we mean that it changes into water vapor.
When the water vapor gets cool enough it condenses, changing to myriads of extremely small drops of water.
Then the water vapor in it condenses into droplets of water, and these form a cloud.
The exact values of these pressures vary with degree of water vapor present and with temperature.
When the air is fully charged with water vapor it is said to be saturated.
|water vapor |
Water in its gaseous state, especially in the atmosphere and at a temperature below the boiling point. Water vapor in the atmosphere serves as the raw material for cloud and rain formation. It also helps regulate the Earth's temperature by reflecting and scattering radiation from the Sun and by absorbing the Earth's infrared radiation. See also vapor.