W&C - Elements - RH

Relative humidity always has a [blank_start]percentage (%)[blank_end] sign.

Relative humidity (%) = [blank_start]Actual amount of water vapour[blank_end] in the air (g/m3) / [blank_start]Maximum amount of water vapour[blank_end] the air can hold ([blank_start]g/m3[blank_end]) x 100%

Relative humidity also varies with [blank_start]temperature[blank_end]. [blank_start]Warm[blank_end] air can hold more water vapour than [blank_start]cool[blank_end] air. When temperature [blank_start]increases[blank_end], the amount of water vapour in the air stays the same, but the rise in temperature makes the air [blank_start]more[blank_end] able to hold water vapour. Thus, relative humidity [blank_start]decreases[blank_end] as temperature increases.

[blank_start]Saturation[blank_end] occurs when relative humidity is at [blank_start]100[blank_end] per cent. Thus, when air holds the [blank_start]maximum[blank_end] amount of water vapour it can hold at a particular temperature, it is said to be [blank_start]saturated[blank_end]. The particular temperature at which saturation occurs is known as the dew point temperature. At [blank_start]dew[blank_end] point temperature, [blank_start]condensation[blank_end] starts to occur. Condensation is a process in which water vapour [blank_start]change[blank_end]s to a liquid known as water droplets by [blank_start]cooling[blank_end].

In order for clouds to form, a few processes need to occur. They are

A cloud is a visible mass of water vapour or ice cubes that are suspended in the atmosphere.