Materials can change state at certain temperatures
EXAMPLE QUESTIONS
What different ‘solid’ materials can you think of?
What different liquid materials do you know?
Air is a mixture of gases.
What other gases do you know?
MATERIALS CAN BE SOLID, LIQUID OR GASES
Solid, liquid and gas are the three states in which matter can exist.
Many kinds of mater can exist in all three states. Water, for example, can be solid when frozen into ice, liquid when it is in its usual form, and a gas when it is steam or water vapour.
Matter can change from one state to another when heated or cooled.
Most solids melt into a liquid when heated and then change into gas when heated to their boiling points.
These changes of state also can be reversed.
Gas can cool into a liquid, and a liquid can cool into a solid.
ALL MATERIALS HAVE MASS
Solids, liquids and gases can all be weighed.
Weight is a measure of the pull of gravity on a mass.
