1. UNIT
9

20. Some materials are
better for a
purpose than
others.

21.  Windows
are made
of glass because
glass is transparent.

22. 
Houses are made from
bricks because bricks
are rigid.

23. Magnetism

24. Some objects are
attracted to magnets.
 These objects are

magnetic.

25.  Only
objects made
from metal are
magnetic.

26. Bending
Twisting
Stretching
Squashing

27. Bend

31. Natural and
Manufacture
d materials

32.  Natural
materials are
made by nature.

33.  Manufactured
materials are made by
people.

34.  Many
materials become
hard when cooled and
soft when heated.