Final answer:
In a rising air mass, when the condensation rate exceeds the evaporation rate, clouds form and precipitation occurs.
Step-by-step explanation:
In a rising air mass, when the condensation rate exceeds the evaporation rate, clouds form and precipitation occurs.
When air rises, it cools down and becomes less able to hold water vapor. As a result, water vapor starts to condense into tiny droplets, forming clouds. If the rate of condensation is higher than the rate of evaporation, the clouds become saturated and precipitation, such as rain or snow, occurs.
For example, when warm, moist air rises in the atmosphere, it expands and cools. As it cools, the water vapor in the air condenses into water droplets, forming clouds. If the rate of condensation is greater than the rate of evaporation, these water droplets grow larger and eventually fall from the clouds as precipitation.