| 2. Water cycle |
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The water cycle is driven
by solar energy. Small, very lightweight droplets of water
rise up into the atmosphere. As they go higher they cool
down, and through condensation they form clouds. Due to
their own weight, clouds release water in the form of
rain or snow that falls to earth.
Water is the only component of our planet that we find
in three natural states: liquid, solid and gas. Depending
on the temperature, water may transform from one state
into another.
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Detecting cause-and-effect relationships.
When we are justified in saying that some event
has been produced by another one we call that a
causal relationship. If someone throws a stone and
breaks a window, we are justified in saying that
throwing the stone caused the breakage of that window.
Finding out what causes something to happen is a
way to find an explanation for it. |
| Complete the sentences with A
CAUSE or AN EFFECT: |
| 1. |
The Evaporation of water is
................................of the Sun’s
heat. |
| 2. |
The condensation of droplets
is ................................of the
formation of the clouds. |
| 3. |
The weight of clouds is ................................of
their releasing rain. |
| 4. |
Low temperature is ................................of
snow. |
| 5. |
Glass becomes liquid as ................................
of an increase in temperature. |
| 6. |
Heat is................................of
snow melting. |
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Music. Listen to Raindrop
by Frédéric Chopin |
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Find out how
the water cycle works in the city or town where you live:
where
water comes from, how is it collected, how is it supplied... |
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| Exercise. Causal
and non-causal sequences, in Wondering at the
World, 6.1.13 |
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| © Grup IREF 2003, with the support of the European Commission, DG XXII (Socrates/Comenius 3.2) |
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