What percentage of Earth's surface is covered by water?
0.51
0.61
0.71
0.81
Which process turns water from liquid to gas in the water cycle?
Condensation
Precipitation
Evaporation
Collection
What is the average time a water molecule spends in the atmosphere before falling as precipitation?
2 days
9 days
15 days
30 days
How many gallons of water evaporate from a large oak tree per day during growing season?
50 gallons
100 gallons
150 gallons
200 gallons
What percentage of Earth's freshwater is frozen in glaciers and ice caps?
0.48
0.68
0.78
0.88
How many clouds can a single gallon of water make?
1 cloud
2 clouds
3 clouds
4 clouds
What temperature does water vapor turn back into liquid water?
32°F
45°F
50°F
60°F
How many Olympic-sized swimming pools could all Earth's clouds fill?
1 million
2 million
3 million
4 million
What percentage of the world's water is drinkable freshwater?
0.01
0.03
0.05
0.07
How many years does it take for the oceans to complete one full cycle of circulation?
500 years
1000 years
1500 years
2000 years
How many water molecules are in a single raindrop?
1 billion
1 trillion
1 quadrillion
2 quadrillion
What's the average speed of a falling raindrop?
5 mph
14 mph
18 mph
25 mph
How much water does the average cloud hold?
500 gallons
1,100 gallons
1,500 gallons
2,000 gallons
What percentage of rain never reaches the ground due to re-evaporation?
0.1
0.15
0.25
0.35
How many times can a water molecule complete the water cycle in one year?
30 times
40 times
50 times
60 times
What's the average depth of a rain cloud?
500 feet
1,000 feet
2,000 feet
3,000 feet
How much water evaporates from Earth's surface each day?
500 trillion gallons
1,000 trillion gallons
1,500 trillion gallons
2,000 trillion gallons
What percentage of Earth's rainfall occurs over the oceans?
0.6
0.7
0.8
0.9
How long can water stay underground as groundwater?
100 years
1,000 years
10,000 years
100,000 years
What's the average size of a raindrop when it falls from a cloud?
2 millimeters
4 millimeters
6 millimeters
8 millimeters
