Nuclear power

Question 1

What can nuclear reactions, including fission, fusion and radioactive decay be?

Answer 1

A source of energy

Question 2

How can a nucleus of U-235 be split?

Answer 2

(via fission) By collision with a neutron and the release of energy as kinetic energy of the fission products

Question 3

What does the fission of U-235 produce?

Answer 3

Two daughter nuclei and a small number of neutrons which can then be absorbed by further uranium nuclei in a chain reaction, provided it is slow-moving enough, so the process is self-sustaining

Question 4

Fusion (The process of…, Nuclei size, Occurs in, Produces, Requires)

Answer 4

• Nuclei joining together
• Small e.g. hydrogen
• Stars
• A large amount of energy and larger, usually stable nuclei
• Very high temperatures and pressures

Question 5

Fission (The process of…, Nuclei size, Occurs in, Produces, Requires)

Answer 5

• Nuclei splitting
• Large e.g. uranium
• Nuclear bombs and reactors
• A large amount of energy, two smaller, usually unstable and radioactive daughter nuclei and 2 or 3 neutrons
• Thermal neutrons to start

Question 6

Nuclear fussion

Answer 6

The creation of large nuclei resulting in a loss of mass from smaller nuclei, accompanied by a release of energy

Question 7

What is the energy source for Stars?

Answer 7

Fusion

Question 8

Why does nuclear fusion not happen at low temperatures and pressures?

Answer 8

Due to the electrostatic repulsions of protons which must have very high kinetic energy to get close enough to fuse