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GCSE Questions: Energy Sources

Q26. Energy from the Sun is released by nuclear fusion.

(a) Provide the missing words:

Nuclear fusion is the joining together of (atomic) nuclei. During nuclear fusion the total mass of the particles decreases.

Never say atoms join together - fusion is a nuclear process not an atomic one!

Mass decreases because some of the mass is changed into energy (E = mc2)

[2 marks]

(b) Nuclear fusion of deuterium is difficult to achieve on Earth because of the high temperature needed.

Electricity is used to increase the temperature of 4.0 g of deuterium by 50 000 000 °C.

Given that the specific heat capacity of deuterium is 5200 J/kg °C, calculate the energy needed to increase the temperature of the deuterium by 50 000 000 °C.

Q = mcΔθ

Energy = mass (in kg) x SHC x temperature change

m = 4.0 g = 4.0 x 10-3 kg

Q = 4.0 x 10-3 x 5200 x 50,000,000

Q = 1,040,000,000 J

Q = 1.04 x 109 J

Q = 1.04 GJ

[4 marks]

(c) The idea of obtaining power from nuclear fusion was investigated using models.

The models were tested before starting to build the first commercial nuclear fusion power station.

Suggest two reasons why models were tested.

Any two from:

to make sure the fusion process is possible

to develop an understanding of the process

to make adaptations to the process

to assess the efficiency of the process

to make predictions

assess safety risks

to assess environmental impact

set-up cost is lower (for small scale experiments)

[2 marks]

(d) Generating electricity using nuclear fusion will have fewer environmental effects than generating electricity using fossil fuels.

Explain one environmental effect of generating electricity using fossil fuels.

Releases carbon dioxide/greenhouse gases which causes global warming/climate chage

OR

Releases particulates which causes global dimming or which causes breathing problems

OR

Releases sulfur dioxide which causes acid rain

OR

Releases nitrogen oxides which cause breathing problems or which cause acid rain

[2 marks]

(Total 10 marks)