Date post: | 22-Jan-2018 |
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1
In general, objects are electrically neutral because they have no
charges in them.
Is the following statement true or false? Explain why.
All objects around us, such as your body or the stars, have
electrical charges.
- Types of electrical charges:
Objects around us usually have the same number of positive and
negative charges, so they are electrically neutral.
Positive
Negative (This moves from place to place)
1 Follow these instructions and write about the results of this
experiment.
Follow your teacher’s instructions to do an experiment with two
balloons, string and a cloth. Explain the results.
1
- Objects with the same charge repel.
- Objects with opposite charges attract.
Look at these pictures, watch these videos and write about
how you can use this in your invention.
2
An electric current is the flow of electrical charges through
materials.
Electrical
charges
Strong electric
current Electricity
Electricity in an
electric current can
be transformed into
other forms of
energy.
Read and discuss.
2
Materials can be:
- Conductors: Electrical charges can move freely through
these materials.
- Insulators: Electrical charges can’t move through these
materials.
Read and write a list of three conductors and three insulators.
Water is also a conductor of electricity. People are made up
mainly of water, so we are conductors of electricity too. For this
reason, it can be very dangerous to use electrical appliances
near water.
When you are going to use an electrical appliance, make sure
that you, the appliance and everything around you are all dry.
Read and speak about security at home.
3
This provides the electricity. The electrical
charges go from one terminal to the other. This transforms
the electrical
energy into
other type of
energy, such
as kinetic or
light energy.
Cables transport the electricity. They
are connecting wires, usually made of
copper, wrapped in plastic covering.
It controls
the flow of
electricity
by closing
or opening
the circuit.
4
In groups, write a list of appliances connected to the electrical grid.
The group with the longest list wins.
A lot of electrical appliances are connected to the electrical grid
through a socket. Every socket is connected by cables to a
national grid.
A national grid gives you the electricity created in power plants.
Read. Where does electricity come from?
4 Read and say if these power plants practise sustainable
development.
Fossil fuels, uranium or
plutonium are used to
heat up the water. This
produces steam, that
moves a turbine which is
connected to a
generator. (Click image to watch video)
Wind moves a
turbine which is
connected to a
generator.
Water moves a
turbine, which is
connected to a
generator.
Heat or light from
the Sun heat water.
The water boils and
produce steam, that
moves a turbine.
THERMAL
POWER
PLANTS
WIND
POWER
PLANTS
HYDROELECTRIC
POWER PLANTS
SOLAR
POWER
PLANTS
4 Debate. Divide the class into four groups and each group will
belong to a power plant. Which one causes the most pollution?
THERMAL POWER
PLANTS
WIND
POWER
PLANTS
HYDROELECTRIC POWER PLANTS
SOLAR
POWER
PLANTS
5
A magnet is an object that attracts other objects made of
magnetic metals.
This attraction is called magnetism.
Magnets have two areas, called poles:
- Opposite poles attract.
- Same poles repel.
Read and answer: What can we use magnetic forces for?
NATURAL MAGNET ARTIFICIAL MAGNET
Magnetite Things made of magnetic metals.
magnetic
forces
Write false sentences to confuse your classmates. Then,
correct your partner’s sentences.
5
The Earth behaves like a giant
magnet and its magnetic poles
are found near the North Pole
and the South Pole.
However, the magnetic poles of
the Earth are opposite to the
geographic poles.
Read and explain to your partner.
north
magnetic
pole
South
magnetic
pole
Work in groups. The needle of a compass is a magnet and its red
part is its north magnetic pole. Why do you think it is used to
orient ourselves?
5
Some animals can notice the Earth’s poles with no compass. This
is very important for migration.
Dictation. Write and discuss.
ELECTRICITY
AND
MAGNETISM
Electrical
charges Electric
current
Electric
circuits Production of
electricity
Magnetism
Negatively charged
Positively charged
Neutrally charged
Flow of electrical charges.
Conductors Insulators
closed
open
Generator
Cables
Switch
Device
Thermal
Wind
Hydroelectric
Solar
power
plants
North
magnetic
pole South
magnetic
pole
Opposite
poles attract
Same poles
repel