Name
Date
Class
Water On Earth
On a separate sheet of paper, explain how fresh water cycles on Earth.
9D
Name
Date
Class
Water on Earth
Understanding Main Ideas
Answer the following questions on a separate sheet of paper.
1. Identify two ways in which water is important to living things.
2. What is the percent of fresh water and salt water on Earth and
where is each type found?
The diagram below shows the water cycle. Use the diagram to answer Questions 3–5.
3. What process is shown at point A?
4. What process is shown at point B?
5. What process is shown at point C?
Building Vocabulary
On a separate sheet of paper, write a definition for each of these terms.
6. groundwater
7. water cycle
9E
8. transpiration
Name
Date
Class
Water on Earth
All the water on Earth flows through the water cycle. Read the passage and look at the
diagram below. Then answer the questions that follow on a separate sheet of paper.
Evaporation, Precipitation, and Runoff
The diagram below shows the yearly global flow of water through the water cycle. The numbers
represent the amounts of evaporation and precipitation over the oceans and over the land.
1. What is the total amount of global evaporation?
2. What is the total amount of global precipitation?
3. How does the total amount of global precipitation compare to the
total amount of global evaporation?
4. Where does more evaporation occur, from the oceans or from the
land? Explain.
5. Where does more precipitation occur, over the oceans or over the
land? Explain.
6. Do Earth’s oceans gain or lose water, considering evaporation and
precipitation together? How much?
7. Do Earth’s continents gain or lose water, considering evaporation
and precipitation together? How much?
8. Compare the differences in evaporation and precipitation over
Earth’s oceans and land. How are they related?
9F
Water on Earth
Answer Key
8. the process by which plants give off water in
the form of water vapor through their leaves
1. The water in the glass was colder than the air
in the room.
2. Sample: No, because if the air and the water
1. 419,000 + 69,000 = 488,000 km3
are the same temperature, there is no reason
for the water to move.
2. 382,000 + 106,000 = 488,000 km3
3. If air containing water molecules becomes
3. Global evaporation equals global precipitation.
warmer than the water molecules, water
droplets will form.
4. Much more evaporation occurs from the
oceans (419,000 km3 compared to 69,000 km3),
because much more of Earth’s surface is
covered by ocean than land.
4. This experiment simulates how rain and other
precipitation is formed.
5. Much more precipitation occurs over the oceans
(382,000 km3 compared to 106,000 km3),
because much more of the Earth’s surface is
covered by ocean than land.
Water evaporates from bodies of water on Earth’s
surface and water vapor is given off through
plant leaves through transpiration. Water vapor in
the atmosphere cools and condenses into liquid
water, forming clouds. When the water droplets
become heavy enough, they fall back to Earth as
precipitation.
6. Since 419,000 km3 of water evaporate while
only 382,000 km3 of water fall as precipitation,
Earth’s oceans lose 37,000 km3 of water.
7. Since 106,000 km3 of water fall as precipitation,
while only 69,000 km3 of water evaporate,
Earth’s land gains 37,000 km3 of water.
8. The oceans lose the same amount as the land
gains. The water that flows into the oceans in
runoff and groundwater balances the two out.
1. Living things use water to perform body
processes needed for survival and as a habitat
2. Salt water: 97%; Fresh water: 3%; salt water
is found in oceans and salt lakes; fresh water is
found in ice sheets and icebergs, in lakes and
rivers, as groundwater, and as water vapor in
the atmosphere.
1. photosynthesis
2. precipitation
3. true
4. condensation
3. precipitation
5. transpiration
6. oceans
4. condensation
7. groundwater
8. gravity
5. evaporation
9. habitat
6. water that soaks into the ground from
precipitation and fills the cracks and spaces in
underground soil and rock layers
7. the continuous process by which water moves
from Earth surface to the atmosphere and
back, driven by gravity and energy from
the sun
9H
10. frozen