Nuclear Fission and Fusion - Paper 1

Question 1

Define nuclear fission

Answer 1

Nuclear fission is the splitting of a large and unstable nucleus (e.g. uranium or plutonium), almost always after absorbing a neutron.

Question 2

Explain the products of nuclear fission.

Answer 2

The nucleus undergoing fission splits into two smaller nuclei, roughly equal in size, and emits two or three neutrons plus gamma rays.
Energy is released, and all the products have kinetic energy.
The neutrons may go on to start a chain reaction.

Question 3

How is nuclear fission different in nuclear weapons and in a nuclear reactor?

Answer 3

In a nuclear reaction, the chain reaction is controlled.
In a nuclear weapon, the chain reaction is uncontrolled.

Question 4

Define nuclear fusion

Answer 4

Nuclear fusion is the joining of two light nuclei to form a heavier nucleus. In this process some of the mass may be converted into the energy of radiation.