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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…
Steel Bridge
Plastic container
Diamond ring
Metal
hammer
head
Leather belt
Fishing rod
ladder
Metal scaffolding
window
towelling
Paper towels/tissues
Elastic band
Stretch fabric
springs
Conductors and Insulators of Heat
1. Some Materials let Heat pass
through them Easily
1) These materials are called
THERMAL CONDUCTORS
2) METALS are good THERMAL
CONDUCTORS
3) Because heat passes through
them quickly – metal normally
feels COLD
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
2) Plastic, cork, wood and fabrics are good
THERMAL INSULATORS
3) Thermal insulators are good for keeping
heat OUT as well as IN
Thermos
Does both
Fridge –
keeps heat
out
Polystyrene
cup – keeps
heat in
Conductors and Insulators of
Electricity
1. 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.
Insulators do not let electricity flow
through them
1. Materials that can not carry electricity are
called insulators – they do not conduct
electricity
2. Wood, plastic, glass and rubber are all
insulators.
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
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

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