Re: Neutrons and Protons in Atoms

Protons and electrons in an atom stay near one another because of forces
of electrostatic attraction between particles of opposite charge. But why
do protons and neutrons stick together in the atomic nucleus? It is even
worse than just drifting apart, because two protons in the same nucleus
would repel one another very strongly, because they have the same charge!

But in nature there are several different sorts of forces. The force of
gravity, for example, which keeps us stuck to the Earth and the Earth
somewhere near the sun, has nothing directly to do with electrostatic
charge.

And there is another sort of force, known as the weak nuclear force, that
makes protons and neutrons attract one another and stick together. At very
close distances - and the nucleus of an atom is very small indeed, much
smaller than the atom - this weak nuclear force is considerably stronger
than the electrostatic force that makes protons repel one another. That is
what makes the nucleus of an atom stick together.

The "weak nuclear force" might seem like a bad name for such a strong force
but there is another different nuclear force, which is apparently even
stronger. But I am only a Chemist, not a Particle Physicist, so I do not
know much about that one!

John.