EVERYDAY SCIENCE

Detailed explanation-1: -As air rises it cools and decreases pressure, spreading out. Clouds form when the air cools below the dewpoint, and the air can not hold as much water vapor. Clouds are made of water droplets or ice crystals that are so small and light they are able to stay up in the air.

Detailed explanation-2: -Clouds form when the invisible water vapor in the air condenses into visible water droplets or ice crystals. For this to happen, the parcel of air must be saturated, i.e. unable to hold all the water it contains in vapor form, so it starts to condense into a liquid or solid form.

Detailed explanation-3: -Temperature’s role Called the dew point temperature, the point of saturation is where evaporation equals condensation. Therefore, a cloud results when a block of air (called a parcel) containing water vapor has cooled below the point of saturation.

Detailed explanation-4: -Clouds are formed when moist air rises upward. As the air rises, it becomes colder. Eventually the air can’t hold all of the water vapor in it, and some of the water vapor condenses to form tiny water droplets. When moist air is cooled at the ground, fog is formed in the same way.

Detailed explanation-5: -As rising air cools, its relative humidity increases. Eventually the relative humidity becomes 100%, the temperature equals the dew point, and a cloud forms. Meteorologists always check the dew points when making a forecast.