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The
Three States of Water
Water can exist in three different forms,
known as States. These states refer to the form that water
takes depending on what is happening to the water molecules. Water
molecules change from one state to another when heat energy is added
or lost. The three states of water are Liquid (flowing water),
Gas (steam), and Solid (ice).
Gas State
The bond between the hydrogen and oxygen
that form the water molecules is a weak attraction.
When water is heated to boiling, and steam begins to form, the molecules
separate and are no longer attached. This causes a gas to form.
In this gaseous state, the water molecules have been heated by energy
and are moving very fast.
Water in the form of gas also forms when
it Evaporates from a liquid . This occurs in the Water Cycle
as oceans, seas, lakes, and smaller bodies of liquid water evaporate
in the heat of the sun.
Liquid State
Water in the liquid state flows. In a liquid
state the molecules are moving more slowly than they move in the
gaseous state because they have lost some of the heat energy.
 Solid
State
Water that is frozen is in the solid state.
When water is cooled down below its freezing point it becomes a
transparent crystalline solid. As the water cools, the molecules
in the water are slowed by the loss of heat energy and do not move
very fast. Water in the solid state has an interesting property,
as it freezes it expands, and as it returns to the liquid state
it contracts.
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