1. UNIT

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. Magneti
sm

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

25.  Only
objects made
from metal are
magnetic.

26. Bending
Twisting
Stretchin
g

27. Bend

31. Natural
and
Manufactur
ed

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.