Nuclear fusion and fission

Question 1

What is a simple explanation of the process of nuclear fission

Answer 1

The splitting of a large atomic nucleus into smaller nuclei

Question 2

explain the process of nuclear fission

Answer 2

1. A neutron is absorbed into a nucleus (commonly of uranium-235 or plutonium-239)
2. The nucleus becomes uranium-236, highly unstable
3. Bonds holding nucleus together are broken and thermal energy is produced
4. 2 daughter nuclei produced as well as some additional neutrons
5. Neutrons collide with other unstable nuclei causing chain reaction

Question 3

What type of energy is present in all products of fission

Answer 3

Kinetic energy

Question 4

How are chain reactions controlled in a nuclear reactor and why

Answer 4

How: control rods made from certain metals are placed between unstable nuclei to absorb stray neutrons

Why: uncontrolled chain reaction could lead to a nuclear explosion

Question 5

Explain how thermal energy from fission reaction can be used to generate power

Answer 5

1) heat from reaction boils chamber of water
2) high pressure steam produced
3) steam turns turbine which turns generator
4) energy produced

Question 6

What is a simple explanation of nuclear fusion

Answer 6

The joining of 2 small and light nuclei form a heavy nucleus

Question 7

Give an explanation of the process of nuclear fusion

Answer 7

2 hydrogen nuclei collide under extremely an high temperature and pressure to form the nucleus of a helium isotope

Question 8

Why does nuclear fusion need to occur under high temperature and pressure

Answer 8

Fusing 2 of the same nuclei is difficult as they repel since they have the same charge (+)
I
So must happen so fast that repulsion of charges don’t have time to stop it

Question 9

When carrying out nuclear fusion on earth, what must the conditions be in comparison to the sun

Answer 9

The temperature must be 10x that of the centre of the sun because the pressure of the sun also contributes to nuclear fusion’s occurence (pressure cannot be recreated on earth)

Question 10

How are nuclear fusion reactors prevented from having their walls vaporised

Answer 10

Powerful magnetic fields used to keep fusion reaction contained

Question 11

Why is nuclear fusion currently not a viable power source

Answer 11

Man made fusion reaction requires more energy to be carried out than is produced

Question 12

Why would nuclear fusion be a much better power source than nuclear fission if it was possible to a higher degree

Answer 12

Only water is needed to provide helium to the reaction and the main waste product is helium which is completely safe