Thanks for the comprehensive review. In passing, I really dislike the magnetic monopole analogy, because such a thing does not exist. it is thus very hard to imagine something that does not exist...
It is preferable to say that there are two forces fighting with each other inside a nucleus: a strong force that is binding the nucleons together and that is short range, and an electric repulsion between the protons that is long range. These two forces behave thus differently depending on the distance between the interacting objects.
In a few words, more neutrons are needed in large nuclei so that we have enough strongly interacting pairs to prevent the electric force from breaking the nucleus apart.
Hmm....that's a great reply indeed.
Thanks a lot @lemouth for your valuable insights on the topic.
I'll definitely try to modify and replace that analogy with something better...
Thank you so much.
Regards
M.Medro
You are welcome! :)