THE STABILITY OF ISOTOPES
2 marks · EasyDescribe what happens to the stability of a nucleus if the number of neutrons is much higher than the number of protons.
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If the number of neutrons is much greater than the number of protons, the nucleus becomes unstable and is likely to undergo radioactive decay.
Also accept: The nucleus becomes unstable if there are too many neutrons compared to protons.
Common mistakes: It becomes more stable; Nothing changes
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Marking points
B1 · 1 mark · States that a nucleus with too many neutrons (compared to protons) is unstable
B1 · 1 mark · Links this instability to radioactive decay or loss of stability
Worked solution
If there are far more neutrons than protons, the balance of forces in the nucleus is upset and it becomes unstable. This can make the nucleus give out radiation to try to become more stable (radioactive decay).