3. USEFUL
MATERIALS
Materials are considered useful when it served a
purpose. These materials may have properties such as
durability,resistance to water,heat or
acid,flexibility,elasticity and hardness
Some useful materials can also be
reused.Materials made of metals,ceramics, wood,
textiles as well as plastics and rubbers are considered
useful materials.
6. HARMFUL
MATERIALS
Materials can be considered harmful when
they are made for certain purpose only and can
cause injury when not used or dispose
properly.Harmful materials may have these
properties: corrosive,flammable or explosive,
poisonous or reactive.
9. 1.Materials that can be recycled
2.Materials that can cause injury.
3.Materials that are toxic to us.
4.Materials that can be dumped straight into the
landfill
5.Matters that can pollute the environment easily
10. 6.Materials that take too much time to decompose
7.Materials that can be used for other purpose
8.Materials that can easily decompose