GCSE Physics

Unstable Isotopes

Add too many neutrons* into the nucleus* of an atom and it will become unstable. This is generally because the forces holding the particles together are too weak overall.

Take too many neutrons from the nucleus, and the positive charges of the protons are not perfectly balanced by the forces between nucleons*. This again makes the nucleus unstable.

In each case it is likely that, given enough time, the nucleus will break up by releasing radiation. What remains is normally more stable, but can still be radioactive.

Related link: Isotopes and Decay Equations

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