The earth has a limited amount of water.That
water keeps going around and around and
around in what we call the "Water cycle".It is the
only way that Earth can be continually supplied
with fresh water.The sun is the most important
part of renewing our water supply.It can be solid
(ice),a liquid (water), or gas (water vapor).
Water on earth is always changing.
How do these changes happen?
It is made up of a few main parts:evaporation
(and transpiration),condensation and
precipitation. Evaporation is when the sun
heats up water in rivers or lakes or the ocean
and turns it into the vapor. The water vapor
leaves the river,lake or ocean and goes into
Condensation is water vapor in the air gets
cold and changes back into liquid, forming
clouds.If heat is taken away from liquid water,
it freezes to become ice.
condenses into millions of small or tiny
droplets that forms a cloud.Clouds lose their water as rain or snow,which is called
Percipitation occurs when so much water has
condensed that the air can't hold it anymore.
The clouds get heavy and heavy and water
falls back to the earth in the form of rain, hail,
snow.It is either absorbed into the ground or
runs off into rivers.Water that was absorbed
into the ground is taken up by plants.Plants
lose water from their surface as vapor back
into the atmosphere. Water that runs off into
rivers flows into the atmosphere. Water that
runs off into rivers flows into ponds, lakes,or
oceans where it evaporates back into the
atmosphere.The cycle continues.