Nuclear Instability

Question 1

State 4 reasons why a nucleus might become unstable

Answer 1

1. It has too many neutrons - decays through beta -
2. It has too many protons - decays through beta+ or electron capture
3. It has too many nucleons - decays through alpha emission
4. It has too much energy - decays through gamma emission (usually because nucleus is excited after decay)

Question 2

Explain why the number of neutrons and protons in a nucleus does not increase uniformly beyond 20 of each

Answer 2

The electromagnetic force of repulsion becomes larger than the strong nuclear force and so more neutrons are needed to increase the distance between protons and therefore decrease the magnitude of the electromagnetic force, to keep the nucleus stable