P6.1 Energy

What happens during nuclear fission?

A large nucleus absorbs a neutron and splits into two smaller nuclei, releasing energy and more neutrons that can trigger a chain reaction.

Why is nuclear power non-renewable?

Nuclear fuel are not replenished in human life times

Describe the energy pathway in a nuclear power station.

Nuclear energy in the fuel heats water; steam turns a turbine; the turbine drives a generator, which transfers energy electrically. Some energy is dissipated as thermal energy.

Why is nuclear power a reliable energy resource?

Electricity generation can be controlled to meet demand

Give one environmental advantage of nuclear power.

It produces very low greenhouse gas emissions

Give two disadvantages of nuclear power.

Nuclear fuels are non-renewable, and radioactive waste must be managed and stored safely for a long time.

Why is nuclear fuel's high energy density an advantage?

A relatively small amount of fuel releases a large amount of energy

What are the three main fossil fuels?

Coal, oil and natural gas.

Why are fossil fuels non-renewable?

They take millions of years to form and are used faster than they are replaced.

What are fossil fuels used for?

Transport, electricity generation and heating.

Why are fossil fuels reliable energy resources?

Fuel can be stored and burned when energy is needed.

How does burning fossil fuels contribute to climate change?

It releases carbon dioxide, which enhances the greenhouse effect.

How can burning fossil fuels cause acid rain?

Sulfur dioxide released during combustion reacts in the atmosphere to form acids.

What other pollution can burning fossil fuels produce?

Harmful gases and particles that pollute the air.

Give one advantage and two disadvantages of fossil fuels.

Advantage: reliable. Disadvantages: finite resources and pollution, including greenhouse gas emissions.

What is a renewable energy resource?

A resource that is naturally replenished as it is used.

Name the renewable energy resources in the AQA specification.

Biofuel, wind, hydroelectricity, geothermal, tides, the Sun and water waves.

What is biofuel?

Fuel made from biological material, such as plants.

Why can biofuels be considered renewable?

The biological material can be regrown.

Why are biofuels not automatically carbon neutral?

Burning releases carbon dioxide; the overall balance depends on absorption during growth and emissions from production.

What is a limitation of wind power?

Electricity generation varies with wind speed.

Why does solar power output vary?

The intensity and duration of sunlight change with weather and time of day and year.

What is hydroelectricity?

Electricity generated using moving water, often released from a reservoir.

Give one advantage and one disadvantage of hydroelectricity.

Advantage: can generate electricity quickly when needed. Disadvantage: reservoirs can flood habitats.

What is geothermal energy?

Energy obtained from heat inside the Earth.

What is tidal energy?

Energy obtained from the movement of tides.

What is wave energy?

Energy obtained from the movement of sea waves.