Why is the combination of two protons and two neutrons stable, but two protons and one neutron is not?
Answer:
There are not enough neutrons to overcome the electrical repulsion of the protons.
Explanation:
Neutrons help stabilize a nucleus by attracting other nucleons (protons and neutrons). Although protons also attract other nucleons using the strong nuclear force, they repel other protons with the electrical force.
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