Answer:
100 %
Explanation:
<em>Relative humidity</em> (RH) is the amount of water vapour in the air compared to the maximum amount it can hold, expressed as a percentage.
RH is measured by a device that has wet- and dry-bulb thermometers.
If the air is unsaturated, water will evaporate from the wet bulb and cool it. The wet-bulb temperature will be less than that of the dry bulb.
If the wet-bulb temperature is the same as the dry-bulb temperature, it means that water cannot evaporate from the wet bulb.
The atmosphere already holds as much water as it possibly can, so the relative humidity is 100 %.
