Clouds and precipitation

Droplets must become large and heavy enough to fall as rain. Exam tip: remember the difference between cloud droplets and raindrops.

Cumulus clouds can grow vertically and become cumulonimbus. Exam tip: connect tall growing clouds with cumulonimbus.

Water vapour cools and condenses to form clouds. In exams, link cloud formation with condensation.

Small droplets are light and can remain suspended in air. In exams, remember droplet size.

Cirrus clouds appear thin and fibrous at high altitude. In exams, link thin streaky form with cirrus.

Stratus clouds spread like a sheet or layer. In exams, remember stratus as layered clouds.

Rain is liquid precipitation: water droplets formed in clouds become large and heavy enough to fall from the atmosphere to the ground. Option C describes condensation, which helps form clouds but is not rain, while option D describes hail, which falls as solid ice. Exam tip: liquid drops indicate rain; solid ice balls indicate hail.

Snowfall falls as ice particles, so it is solid precipitation. In exams, connect snowfall with ice.

Water vapour can change into droplets on condensation nuclei. In exams, treat nuclei as the base for droplet formation.

Hailstones are hard icy balls falling from clouds. In exams, connect hail with solid precipitation.

Drizzle is light rainfall with very small drops. In exams, link tiny drops with drizzle.

Cumulonimbus clouds can grow very high and bring thunder and heavy rain. In exams, link storm clouds with cumulonimbus.

A mountain forces moist air upward and cools it. In exams, link mountain barrier with orographic rainfall.

Strong heating makes air rise and cool, which can produce rain. In exams, connect hot ground with convectional rain.

Cyclonic rainfall forms with low pressure and air convergence. In exams, take low pressure as a clue.

Large and heavy droplets fall toward the ground due to gravity. In exams, remember droplet weight and gravity.

Clouds are connected with condensation and precipitation in the water cycle. In exams, link clouds with the water cycle.

Fog is a suspension of tiny water droplets very close to the Earth’s surface, so it reduces visibility near the ground. Clouds are also made of water droplets or ice crystals, but they generally occur higher in the atmosphere. Option A reverses this relationship. Exam tip: a cloud at or very near ground level is called fog.

Rain is a form of water falling from the atmosphere to the ground. In exams, remember rain as a simple example of precipitation.

Dense water-rich clouds pass less light and look dark. In exams, connect dark clouds with rain possibility.