i know that the last couple of topics are missing but i have only studied up to generating electricity

hope this is useful :)

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  • Created by: Sophia
  • Created on: 22-05-13 21:40
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Energy Transfer
· Energy can be transferred by conduction, convection, evaporation and condensation.
All these processes involve particles.
Is the movement of thermal energy through a material without the particles in the material
Glass, wood and plastic are all poor conductors of heat.
Heat is the kinetic energy of particles as they vibrate. If we heat the particles at one end of
a material the particles at that end vibrate more (have more kinetic energy) and bump into
the neighbouring particles which causes them to vibrate more. They collide with their
neighbours and so the energy is passes from one particle to another through the material.
Metals are very good conductors of heat energy because there is a second process at work.
Metals have free electrons, the free electrons gain extra kinetic energy at the warm end of
the material. They diffuse to cooler areas where they collide with the particles in the
material transferring their kinetic energy.
Convection happens in fluids (liquids & gases).
Hot liquids and gases rise because when they are heated they expand and become less
dense. The less dense warm liquid or gas then floats up through the more dense cold liquids
and gases.
Cold liquids and gases sink because when cooled they contract and become more dense.
The more dense cold liquids and gases sink down through the less dense warm liquids and
These changes in density cause the convection currents in the liquid or gas.
In a liquid the particles have a range of energies. At the surface of the liquid some particles
will have enough energy to escape from the liquid and overcome the attraction of the other
liquid particles. This leaves the less energetic particles still in the liquid and so the liquid is
To make a liquid evaporate more quickly you could;

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· increase the surface area of the liquid
· pass air across the surface of the liquid
Condensation is the change of state from a gas to a liquid, it is caused by cooling. For
example water vapour in warm air condenses into a liquid when cooled.
Infrared Radiation
Infrared radiation is the transfer of energy from one
place to another by an electromagnetic wave.
All objects emit and absorb infrared radiation. The hotter an object is the more energy it
radiates per second.…read more

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Solid, Liquid and Gas
Substances can change from one state to another. Kinetic theory can explain the change of
state by considering all matter (substances) to be made of particles.
· Solid, particles are closely packed in a regular arrangement. The particles vibrate
about a fixed position.
· Liquid, particles are closely packed in a random arrangement. The particles can
move through the liquid but they cling together.
· Gas, The particles are far apart. There motion is random and independent of the
other particles.…read more

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Specific heat capacity
This is a measure of the amount of energy required to raise the temperature of 1kg of a
material by one degree Celsius.
heat transferred = mass x specific heat capacity x temperature change
(joules, J) (kilogram , kg) ( joules / kilogram oC) (degrees Celsius, oC)
Example; How much energy is needed to raise the temperature of 1 kg of water by 30 oC.
The specific heat capacity of water is 4200 J/kgoC.…read more

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· replacing old cars with new more efficient ones
Energy Transfers -types of energy
There are nine types of energy;
· Magnetic energy
· Kinetic (movement) energy
· Heat (thermal) energy
· Light
· Gravitational potential energy
· Chemical energy for example in coal and petrol
· Sound energy
· Electrical energy
· Elastic potential energy
· Nuclear energy
· Most Kids Hate Learning GCSE Energy Names
The ratio of energy which was transferred to a useful form compared to the total energy
initially…read more

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We can use the squares on the graph paper to work out the efficiency of the device
represented by this Sankey diagram.
The National Grid
Electricity is transferred from the power station to
consumers along the national grid. The power lines across
the country connect together all the power stations with all
the people who want to use electricity.
Advantages of the national grid;
· electricity can be used from any power station to meet demand in any part of the
country.…read more

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The fossil fuels used to generate electricity are coal, oil and natural gas. They release
heat energy when they are burned, and can therefore be classified as a fuel. They were
formed from the remains of living organisms millions of years ago and are called
fossil fuels. About three-quarters of the electricity generated in the UK comes from
power stations fuelled by fossil fuels.
There are some disadvantages to burning fossil fuels to generate electricity.…read more

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heat energy is used to boil water. The kinetic energy in the expanding steam spins
turbines, which then drive generators to produce electricity.
The advantage of this process is that:
Nuclear fuels do not produce carbon dioxide
Or sulphur dioxide.
The disadvantages of this process are that:
Nuclear fuels are non-renewable energy
If there is an accident, large amounts of radioactive material could be released
into the environment.
In addition, nuclear waste remains radioactive and is hazardous to health for
thousands of years.…read more

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Wind farms are noisy
They may spoil the view for people living near them.
The amount of electricity generated depends on the strength of the wind.
If there is no wind, there is no electricity.
Tidal Energy:
Tidal barrage is when huge amounts of water move in and out of river mouths each day
because of the tides. A tidal barrage is a barrier built over a river estuary to make use of
the kinetic energy in the moving water.…read more

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Wave energy is when the water in the sea rises and falls because of waves on the surface.
Wave machines use the kinetic energy in this movement to drive electricity
generators.…read more


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