A transition from one state to another is called change of state

1. CHANGE OF STATE

2.  Matter normally exists in three states:
SOLID , LIQUID, GAS
 A transition from one of these states to another is
called CHANGE OF STATE.
 Two common changes of states are,
SOLID → LIQUID
LIQUID→ SOLID and vice versa
 These changes occur when the exchange of heat
takes place between the substance and its
surroundings.

3. CHANGE OF STATE OF ICE ON
HEATING

4.  MELTING:
The change of state from solid to liquid.
 FUSION:
The change of state from liquid to solid.
 VAPORISATION:
The change of state from liquid to gas.
 SUBLIMATION:
The change of state from solid to vapour
state without passing through the liquid state.

5. time(min)
It is observed that the
temperature remains
constant until the entire
amount of the solid
substance melts.
ie, both the solid and liquid
states of substance
coexist in thermal
equilibrium during the
change of state from solid
to liquid.
MELTING POINT
The temperature at
which a solid is
converted into
liquid.

6. It is observed that
the temperature
remains constant
until the entire
amount of the
liquid is converted
into vapour.
BOILING POINT
The temperature at which
the liquid and the vapour
states of the substance
coexist.

7. REGELATION
When pressure is
applied, ice melts
at low temperature.
If pressure is
removed, water
refreezes.
APPLICATION
skating on snow due to
the formation of water
below the skates.