Water Cycle — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. What happens to water when the sun heats it?
A) It freezes
B) It evaporates
C) It turns red
D) It disappears
The sun's heat warms water and turns it into invisible vapor that rises into the air. This change from liquid to gas is called evaporation.
2. What is it called when vapor turns back into tiny drops?
A) Evaporation
B) Collection
C) Condensation
D) Melting
Condensation happens when water vapor cools high in the sky and changes back into tiny liquid drops. Those tiny drops are what form clouds.
3. Where does most of Earth water collect?
A) In clouds
B) In the ocean
C) On mountaintops
D) In the desert
Oceans cover most of Earth's surface, so the largest amount of water collects there. Rivers and rain eventually flow back into the ocean.
4. Which step of the water cycle makes rain or snow?
A) Evaporation
B) Collection
C) Condensation
D) Precipitation
Precipitation is the step where water falls from clouds to the ground as rain or snow. It happens after the cloud drops grow too heavy to stay in the sky.
Part B: Fill in the Blank
Write the correct answer on each line.
1. Evaporation happens when the sun heats water.
Heat from the sun warms puddles, lakes, and oceans until tiny bits of water rise into the air as vapor. Without the sun's warmth, evaporation would not start.
2. Tiny water drops in the sky group together to form clouds.
High in the sky, tiny water drops bump into each other and stick together. When millions of these drops gather, they make the fluffy clouds we see.
3. When clouds cannot hold more water, rain falls.
Clouds can only hold so many water drops before they get too heavy. Once that happens, the drops fall back to Earth as rain.
4. After rain, water flows into rivers during collection.
Collection is the step where rainwater gathers and runs downhill into streams, rivers, lakes, and oceans. The water joins together in these big places after a storm.
5. The water cycle is powered by energy from the sun.
Energy from the sun keeps the whole water cycle moving by heating water so it can evaporate. Without sunshine, water would not rise, clouds would not form, and rain could not fall.