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Why can't neutrons combine without protons?
Neutrons hold atoms together with their contribution to the strong nuclear force. Without them protons would repel and fly apart. Why then do neutrons not stick together all the time? They are unstable yet I don't see what is making them fly apart.
Neutrons and the repelling protons ==Stable
neutrons and NO repelling protons== unstable
Obviously there is more going on than I realize. I googled and wikipediaed and I am still confused. Help me
Neutrons do nothing? If that was true then why does the ratio of neutrons to protons approach 1:1 as mass increases? Neutrons have the strong nuclear force which is needed to hold atoms together. Atoms may have an AVERAGE charge of zero because of the equal number of electrons but in the nucleus the protons are trying their best to force each other apart. The neutrons hold it all together.
2 Answers
- morningstarLv 78 years agoFavorite Answer
I wondered the same thing. The contrast is particularly striking when you consider deuterium vs. a hypothetical dineutron. Deuterium is stable but the dineutron fissions. Since there is only one proton in deuterium, electrostatic force doesn't come into play yet. The only difference between a proton and a neutron in the context of deuterium vs. the dineutron is that the proton and neutron are distinct particles. That means the Pauli exclusion principle is at work in the dineutron, and not in deuterium.
Because of the Pauli exclusion principle, in the dineutron the neutrons must take opposite spin. In deuterium they are free to take the same spin. Supposedly it is more attractive to take the same spin, so that is what happens in deuterium. The opposite spins in the dineutron have a repulsive or energy-increasing effect. As a result, it has just barely positive energy, which by definition is negative binding energy. The dineutron is just barely unbound. Deuterium just barely has positive binding energy; it is just barely bound.
I still have a hard time understanding this spin effect. I tried to understand it in terms of magnetism, but later I read somewhere that it is a strong force effect related to spin (some sort of "strongomagnetism" maybe?)
