The water cycle
About what percent of all the water in earth's water cycle is stored in ice?
Nearly 2 percent.
Is runoff water purified?
No, it moves too fast.
Where does water evaporate from?
Oceans, large lakes, small puddles, the soil, and even from your skin.
Where does most of the precipitation fall?
On oceans.
What is a condensation nuclei?
Particles that serve as surfaces onto which water vapor condenses.
What processes use infiltration?
Water that circulates on as ground water.
About how long do most water molecules spend in the atmosphere before falling back to earth in the form of precipitation?
10 days
What do the water molecules in the surface water do when the sun heats the earth's surface?
Absorb the radiation from the sun.
How do the water molecules get back to earth?
As more and more water vapor condenses around the condensation nuclei, the cloud becomes so heavy that some of water begins to fall back to earth. Precipitation!
What is the process of water molecules absorbing the sun's energy, then moving to the gaseous state, called?
Evaporation.
Ice sheets, icebergs and glaciers are the largest reservoir for what on earth?
Freshwater.
How is water "purified" in the water cycle?
Infiltration
What happens to precipitation that falls on land?
It could evaporate right away, it could move as runoff in rivers, streams or small gullies (it might make it to a larger body of water like the ocean), it could sink into the soil and become groundwater (groundwater moves underground and eventually reaches a larger body of water such as the ocean).
Why is groundwater purified?
It moves slowly as it makes it's way through a filter of rock and soil.
What is transpiration?
The process by which a plant loses water to the atmosphere by way of evaporation of water from the plant through the surfaces of its leaves.
What is the source of energy for the water cycle?
The sun
What happens to the water molecule when it evaporates?
The water molecule rises on warm air. As the air cools (as it rises) the water condenses and may clump around a dust particle or a condensation nuclei. This is how clouds form.
What is another way water enters the atmosphere?
Transpiration
When do the water molecules start to evaporate?
When they have absorbed enough energy to change from liquid to gas.
Is evaporated water purified?
Yes, evaporation changes the water into a different state, leaving behind the other substances that might be in the water.
The water given off by plants, is it purified?
Yes, plants will only release water, leaving behind any other particles.
