There are three states of matter: solid, liquid, and gas. Substances can change states through melting or boiling by absorbing energy. When a solid melts, its temperature remains constant as it changes to a liquid, and when a liquid boils, its temperature remains constant as it changes to a gas.

1. IP1.3.3 Changes of state
Changes of state
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2. IP1.3.3 Changes of state
States of matter
The three states of matter are solid, liquid and gas.
The state of matter of a substance can be changed
through melting and boiling.
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3. IP1.3.3 Changes of state
Changes of state
When something melts it takes in energy to change from a solid
to a liquid. When something boils it needs energy to change
from a liquid to a gas.
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4. IP1.3.3 Changes of state
 When you heat a solid its temperature rises at a steady rate
until it reaches melting point. Then the temperature remains
constant as it melts.
 If you heat the liquid it will rise at a steady rate again until it
boils. Then the temperature remains constant as it turns into a
gas.
 The rate of temperature rise of the solid and liquid will not be
the same.
Graph of
temperature
against time
for ice being
heated at a
constant rate
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5. IP1.3.3 Changes of state
The temperature of this ice cube stays the same while it melts.
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6. IP1.3.3 Changes of state
The temperature of this water stays the same as it turns into a gas.
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