Water Cycle — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Water from lakes goes up as vapor.
When the sun shines on a pond, its heat changes the top of the water into invisible water vapor that floats up into the air.
2. Vapor rises and forms a cloud.
As water vapor rises into the cooler sky, it sticks together into tiny drops, and those drops group up to make a cloud.
3. Heavy clouds drop rain to the ground.
Clouds can only hold so much water. Once there are too many drops, the cloud cannot hold them and they fall down as rain.
4. Rain flows into rivers and lakes.
The ocean is the biggest body of water on Earth, and most of the rain that falls eventually flows into it through rivers and streams.
5. The sun heats the water to start the cycle.
The water cycle never finishes because the sun keeps heating the water, so the same water goes around and around — again and again.
6. Water keeps moving in a cycle.
Precipitation is the science word for any water that falls from the sky, whether it's rain, snow, sleet, or hail.
7. Puddles dry up because of the sun.
Even though a cloud looks like one big white puff, it is really made of millions of super tiny water drops too small to see one at a time.
8. Cold air turns vapor back into water drops.
The sun is like the engine for the water cycle — its warm rays heat the water so it can turn into vapor and begin the journey up into the sky.
9. A river carries rainwater to the ocean.
Evaporation is the special name for when liquid water warms up and changes into water vapor, a gas that floats up into the air.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
rain
→ water falling from sky
water falling from sky
vapor
→ water turned to gas
water turned to gas
cloud
→ fluffy shape in sky
fluffy shape in sky
cycle
→ goes round and round
goes round and round
Each step of the water cycle does a different job: evaporation takes water up as vapor, condensation makes drops in clouds, precipitation lets water fall back down, and collection gathers water in lakes and oceans.