Water Cycle — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. What happens when the sun heats water in a puddle?
A) It freezes
B) It turns to vapor
C) It turns red
D) It gets bigger
When the sun warms water, it turns into a gas called vapor and floats up into the air. This change is called evaporation.
2. What is it called when vapor turns back into water drops?
A) Evaporation
B) Precipitation
C) Condensation
D) Melting
Condensation happens when warm vapor meets cool air and turns back into liquid water drops, the way water forms on the outside of a cold cup.
3. Where does rain go after it falls on the ground?
A) Into outer space
B) Into rivers and lakes
C) It disappears
D) Back up right away
Oceans cover most of Earth's surface, so they hold the biggest amount of water on our planet. Rivers and rain eventually flow into them.
4. Which step comes first in the water cycle?
A) Rain falls down
B) Snow melts
C) The sun heats water
D) Clouds move away
Precipitation is the step when water falls from clouds down to the ground. Rain, snow, sleet, and hail are all kinds of precipitation.
Part B: Fill in the Blank
Write the correct answer on each line.
1. When water heats up and rises, it is called evaporation.
The sun is our biggest source of heat, and its warm rays are what make water change into vapor. Without the sun, evaporation would not happen.
2. Vapor cooling into water drops is called condensation.
Clouds are made when millions of tiny water drops gather together high in the sky. That is why clouds look like big puffy shapes.
3. Rain and snow falling down is called precipitation.
Clouds can only carry so many water drops. When they become too heavy, the drops slip out and fall to the ground as rain.
4. The water cycle starts over because of the sun.
Collection is the water cycle step where fallen rain gathers into rivers, lakes, and oceans as it flows across the land.
5. Water moves from the ground to the sky and back again.
The sun gives the heat energy that starts evaporation and keeps the whole cycle turning. It is the engine that powers the water cycle.