Weather and Seasons — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. What is the first step of the water cycle?
A) Precipitation
B) Condensation
C) Evaporation
D) Collection
Evaporation comes first because the sun's heat must turn liquid water into vapor and lift it into the sky before clouds can form or rain can fall.
2. What happens during condensation?
A) Water falls from the sky as rain.
B) Water vapor cools and forms tiny droplets.
C) The sun heats up a lake.
D) Snow melts into a river.
During condensation the rising vapor reaches the cold upper air, where it loses heat and the gas changes back into the tiny liquid droplets we see as clouds.
3. Where does most of the water on Earth evaporate from?
A) Rivers
B) Ponds
C) Oceans
D) Puddles
Oceans cover about three-quarters of Earth's surface, so they hold the most water and far more vapor rises from them than from any lake or river.
4. What provides the energy that keeps the water cycle going?
A) The moon
B) The wind
C) The sun
D) The clouds
The sun is the energy source that warms the water and keeps the cycle going; without sunlight, water could not evaporate or move through the sky.
Part B: Fill in the Blank
Write the correct answer on each line.
1. When water evaporates it changes from a liquid into a gas.
Heat gives water molecules enough energy to break apart and float into the air as water vapor, which is the gas form of water.
2. Tiny water droplets in the sky group together to form clouds.
When millions of tiny water droplets stick together around dust in the cool air, they create the visible white shapes we call clouds.
3. After rain falls on land it flows into streams, rivers, and oceans.
Gravity pulls rainwater downhill, so it travels from streams into rivers and finally back into the oceans, where the water cycle can begin again.
4. The water cycle repeats over and over, so it is called a cycle.
A cycle is something that keeps repeating in a loop, and water keeps moving from oceans to sky to land and back again, so we call it the water cycle.
5. Plants release water vapor into the air through their leaves.
Plants pull water up through their roots and release it as vapor through tiny holes in their leaves, a process scientists call transpiration.