Nuclear Instability

Introduction
 

Not all atomic nuclei are stable. Some nuclei are unstable because the forces acting within the nucleus are unbalanced, causing them to undergo radioactive decay. Nuclear instability depends on the balance between the attractive strong nuclear force and the repulsive electrostatic force between protons. Understanding why nuclei become unstable helps explain radioactive decay and the production of ionising radiation.
 

AQA A Level Physics Specification: 3.8.5 Nuclear Instability
 

What You Need to Know
 

• Explain why some atomic nuclei are unstable.

• Describe the roles of the strong nuclear force and electrostatic repulsion within the nucleus.

• Explain how the neutron-to-proton ratio affects nuclear stability.

• Describe why very large nuclei are more likely to be unstable.

• Explain how radioactive decay increases the stability of a nucleus.

• Understand the concept of the band of stability.

• Relate nuclear instability to alpha, beta and gamma decay.

• Apply your understanding of nuclear stability to explain radioactive behaviour.
   

Downloadable Topic Pack
 

Nuclear Instability Topic Pack Exam Questions and Answers
 

This downloadable resource contains carefully selected AQA A Level Physics exam questions covering nuclear stability, the strong nuclear force, electrostatic repulsion, neutron-to-proton ratio and radioactive decay, together with fully worked solutions designed to strengthen understanding and improve exam performance.
 

Related Topics
 

• Radioactive Decay

• Alpha, Beta and Gamma Radiation

• Rutherford's Alpha Scattering Experiment

• Nuclear Radius

• Binding Energy