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3 states
◦ Solid
◦ Liquid
◦ Gas
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The 3 states of water are controlled by
temperature
The amount of water on earth remains the
same even if it changes states
70% of Earth’s water is in the ocean
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The sun in the energy
force that powers the
water cycle
The sun heats oceans,
lakes, rivers and
causes water to change
from liquid state to
gaseous state
During evaporation the
impurities found in
water (salt) are left
behind
◦ This is important because
97% of water is salt water
found in our oceans
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When temperatures
decrease the water
vapour (gas) changes
back into liquid
Condensation is the
opposite of
evaporation
Small water droplets
are formed in the
atmosphere
Collections of water
droplets form clouds in
the sky or fog at
ground level
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Tiny water droplets
bounce around in a cloud
and as they hit each
other they stick together
and become larger
The clouds get to heavy
and eventually water falls
back to the Earth
Precipitation can occur in
the form of rain, sleet,
snow or hail
Most precipitation falls
back into the oceans or
onto land
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About 1/3 of water that returns to Earth as
precipitation runs off the surface of the land
into streams, rives, lakes and oceans
The other 2/3 of precipitation is evaporated,
transpired or infilrated into ground water
Surface run off is an important part of the
water cycle as it returns water into the bodies
(rives, lakes and oceans) where evaporation
occurs
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Not all surface run off water flows back into
streams, rivers, lakes and oceans. Some of it
soaks into the ground
Infiltration is the downward movement of water
from the land surface into soil or underlying
rocks
This water can replenish aquifers, which store
large amounts of fresh water
Some infiltration stays close to the land surface
and can seep back into surface water bodies
Some ground water finds openings into the land
surface and comes out as fresh water springs
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Water is returned to
the atmosphere by
plants
Water is absorbed by
plants (through the
roots) from water
found in the soil
The water travels up
through the plant
and then is
evaporated back into
the atmosphere from
the plants leaves