Despite the similar nature of charges,protons remain inside the nuclear dimension.why?
Your question is not very clear. Can you be more precise? The similar nature of charges of protons and what?
Indeed, many of your questions are not very clear. It would probably help if you spent more time composing them, thinking about exactly the sort of answer you are looking for.
I think he means, similar to each other. If like repels like, how does the nucleus stay so small?
Classically speaking it's easy to think of it in the following way:
Even if you have a repeling force (electromagntic), you still have an attractive one (nuclear force). So at the end as long as those two cancel each other out, protons can stay together. For larger nuclei with many protons, there needs to be enough neutrons too in order for the nuclei to be stable (as a general rule)....
Quantum mechanically you have a very complex dynamical system that exists in a bound state.
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