Materials are considered useful when they serve a purpose and have properties like durability, resistance to water/heat/acids, flexibility, elasticity, and hardness. Useful materials include metals, ceramics, wood, textiles, plastics, and rubbers. Materials can be considered harmful if they are only meant for a specific purpose and can cause injury if not used or disposed of properly, with properties like being corrosive, flammable, explosive, poisonous, or reactive. Examples given are bleach and car batteries. The document asks the reader to identify which materials can be recycled, cause injury, are toxic, can be landfilled, easily pollute, take long to decompose, can be reused, or

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.

4. BOOKS

5. FRUIT PEELING

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.

7. BLEACH
when not properly used may
damage your lungs and organs

8. CAR BATTERIES
are highly corrosive and
harmful to the environment
when not properly used.

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

11. REVIEW
When do we say that
material is useful?harmful?

12. USEFUL HARMFUL

13. empty hair spray plastic bottle
drained batteries empty disinfectant
bottle
used paint brush food carton
vegetable scraps used syringe
old newspaper old clothes

14. useful harmful