Earth's Systems: Water and Weather — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
Runoff is water that soaks deep into underground rock layers.
Corrected: Runoff is water that flows over the land's surface into streams and rivers.
Infiltration describes water soaking into soil; runoff describes water flowing over the surface.
2. Fix the sentence:
The hydrosphere includes all of Earth's rocks and mountains.
Corrected: The hydrosphere includes all of Earth's water in oceans, lakes, rivers, and ice.
The hydrosphere is the water sphere; the geosphere covers rocks, soil, and landforms.
3. Fix the sentence:
Climate can change overnight when a storm passes through.
Corrected: Weather can change overnight when a storm passes through.
Climate shifts slowly over decades, while weather can change within hours or even minutes.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. Water that soaks into the soil and reaches groundwater is called infiltration.
Infiltration replenishes underground aquifers that supply wells and feed springs and streams.
2. Water flowing across the land into rivers and lakes is called runoff.
Runoff carries rainwater and melted snow across landscapes, sometimes causing erosion or flooding.
3. All living things on Earth, including plants and animals, make up the biosphere.
The biosphere includes every organism, from microscopic bacteria to massive forests and ocean creatures.
4. The layer of gases surrounding Earth is called the atmosphere.
The atmosphere holds the air, weather, and gases that protect and warm Earth's surface.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Why does water vapor rise into the sky during evaporation?
Sample answer: Heat from the Sun gives water molecules energy, making the warm vapor less dense than the surrounding cooler air, so it rises.
Understanding density and heat helps explain why clouds form high in the atmosphere.
2. Give one example of weather and one example of climate.
Sample answer: A thunderstorm this afternoon is weather, while Arizona being hot and dry most of the year is climate.
Concrete examples make the time-scale difference between weather and climate clearer.