1. Materials and their
Properties

2. Comparing Materials
Materials have certain PROPERTIES which make them USEFUL
We need to be able to describe and compare the properties of a material and say why its used for a job. We use certain materials for certain jobs…

3. strong
Steel Bridge
Plastic container

4. hard
Metal hammer head
Diamond ring

5. flexible
Leather belt
Fishing rod

6. Rigid
Metal scaffolding
ladder

7. transparent
window

8. absorbent
Paper towels/tissues
towelling

9. stretchy
Stretch fabric
Elastic band

10. squashy
springs

11. Conductors and Insulators of Heat
Some Materials let Heat pass through them Easily
These materials are called THERMAL CONDUCTORS
METALS are good THERMAL CONDUCTORS
Because heat passes through them quickly – metal normally feels COLD

12. Some Materials Do Not let Heat pass through them
1) Materials that do not let heat pass through them are called THERMAL INSULATORS.
Oven glove
Wooden handle
thermals

13. Polystyrene cup – keeps heat in
2) Plastic, cork, wood and fabrics are good THERMAL INSULATORS
3) Thermal insulators are good for keeping heat OUT as well as IN
Fridge – keeps heat out
Polystyrene cup – keeps heat in
Thermos
Does both

14. A good insulator =
a poor conductor

15. Heat travels from
a warmer material
to a colder one

16. Conductors and Insulators of Electricity
Conductors let electricity flow through them
1)Materials that can carry electricity are called conductors – they conduct electricity
2) Metals like copper, iron, steel and aluminium are all good conductors.

17. Insulators do not let electricity flow through them
Materials that can not carry electricity are called insulators – they do not conduct electricity
Wood, plastic, glass and rubber are all insulators.

18. Insulators and Conductors both have important Uses
Wires are coated in plastic – electricity cant flow through it so you don’t get a shock if you touch it
Copper wire allows electricity to flow through
A plug has metal pins – conduct electricity, insulated flex and a plastic cover to hold

19. Electricity can be dangerous
You shouldn’t tough anything electrical with wet hands – and that includes switches.
Electricity can be conducted through sweat (salty water) to your body, giving you and electric shock
Remember – water conducts electricity