Nuclear fission and fusion

Question 1

What is nuclear fission

Answer 1

The splitting of large,unstable nuclei to form smaller more stable nuclei

Question 2

Give an example of a fissionable isotope

Answer 2

Uranium-235

Question 3

What usually needs to happen to induce fission?

Answer 3

-The unstable nuclei must absorb a neutron
-Spontaneous fission(where no neutron absorption occurs)is rare

Question 4

Alongside 2 smaller nuclei, what else is emitted in a fission reaction

Answer 4

• 2 or 3 neutrons
• Gamma rays
• Energy

Question 5

What form of energy do all fission products

Answer 5

Kinetic energy

Question 6

What takes place during a chain reaction in a nuclear factor

Answer 6

• An unstable nucleus absorbs a neutron
• The nucleus undergoes fission and releases 2 or 3 further neutrons
  -These induce more fission, which results in a chain reaction

Question 7

What is the consequence of an uncontrolled chain reaction

Answer 7

• The rate of fission events becomes to high and results in the production of too much energy
• This can lead to a nuclear explosion

Question 8

What are the 3 main components of the core a nuclear reactor

Answer 8

1. Fuel rods
2. Control rods
3. Moderator

Question 9

What is the role of the moderator in a nuclear reactor?

Answer 9

To slow down the neutrons so they are travelling at speeds which allow them to be absorbed
by fissile nuclei and cause fission