P6

Question 1

Simply, what is nuclear fission?

Answer 1

A nuclear reaction, which releases energy from large and unstable nuclei by splitting them into smaller nuclei.

Question 2

What are the two ways in which nuclear fission can occur?

Answer 2

Spontaneously

The nucleus absorb a neutron making it unstable and causing it to split.

Question 3

What are the products of nuclear fission and where do they go?

Answer 3

• Split nuclei (radioactive)
• Energy taken away by gamma radiation
• Energy stored in kinetic energy store of fission products.

Question 4

How does a chain reaction of nuclear fission occur?

Answer 4

E.g. uranium, nuclear fission occurs, spits out some neutrons, makes some other nuclei unstable causing them to split and so on.

Question 5

Name an industrial use of nuclear chain reactions. What is the energy used for?

Answer 5

• Nuclear power stations generate electricity.
• Use uranium and plutonium as fuel
• Energy released used to heat water to drive a steam turbine connected to electricity generator.

Question 6

What is the issue with nuclear waste?

Answer 6

• The products are radioactive and have long half lives, difficult and costly to dispose of safely.

Question 7

What is nuclear fusion?

Answer 7

Fusing of two light nuclei, e.g. two hydrogen nuclei to make a hydrogen nucleus.

Question 8

Compared to fission, what are the products of nuclear fusion?

Answer 8

• More energy per given amount of fuel.

- 1 nucleus instead of two.

Question 9

Why is so much energy released during nuclear fusion?

Answer 9

• The 2 nuclei means the mass of the nucleus (product) is always higher, but the extra mass is converted to energy and carried away by radiation.

Question 10

What waste is there in nuclear fusion?

Answer 10

No radioactive waste

Question 11

In what conditions do fusion occur?

Answer 11

• Very high temperatures (10million degrees C)

- To store hydrogen, very strong magnetic fields are needed.