Page 49 - Science Class 6 Times Publication

Observation: The balloon gets in ated. This is due to expansion of
the gas contained in the vessel.

Conclusion: Gas expands on heating.
Heat causes the change in states of matter

When solid substance is heated, it changes to liquid. Similarly, when
liquid is heated, it changes to gas.

In the same way, gas changes to liquid and liquid changes to solid on
cooling.

Activity 4.7
To show change of state of matter due to heat

Materials required: Test tubes, ice cubes, burner, test tube holder etc.

Ice Water Water vapour

Procedure
1. Take some ice cubes in a test tube.
2. Heat the ice. What happens?

3. Heat the water further. What happens?

Observation: The ice (solid) melts into water when it is heated. The
water (liquid) changes to vapour (gas) on further heating.

Conclusion: Matter changes its state due to heat.

Absorption of heat

When we sit in the sun in hot sunny days wearing black clothes, we
feel hotter. When we wear white clothes, we do not feel such hotness.
In the same way, when we cook foods in the pots having black and

Times' Crucial Science and Environment 45 Book 6