# Strong nuclear force vs electrostatic repulsion between protons

Does the strong nuclear force balance the electrostatic repulsions between the protons or does it overcome the repulsion?

I looked up on wikipedia and it says that the strong nuclear force is strongest of all the fundamental forces. Based on that i assume that it overcomes the electrostatic repulsions.

Now what if there are more protons than neutrons (or less neutrons than protons), in the nucleus? Wouldnt this mean that the electrostatic forces are stronger than the strong nuclear force?

If the electrostatic forces are stronger, what would happen to the nucleus? Would it break apart? (is it related to the stability?)

In addition to this, at what stage do we know (or by how much in the difference between protons and the neutrons) would cause the electrostatic forces greater than the strong nuclear force?

Thankyou.

• Protons are all positively charged. They repel each other electrostatically. – probably_someone Jan 22 '19 at 2:47
• @probably_someone yeah i realise,\ – GoNK Jan 22 '19 at 3:28
• There are a couple of great answers to this related question: physics.stackexchange.com/questions/323350/… While they don't exactly answer your question, they have useful info that will put your question in perspective. – PM 2Ring Jan 22 '19 at 3:45
• @PM2Ring cheers. I would be delightful if you can too answer my question. – GoNK Jan 22 '19 at 4:23

## 2 Answers

"Does the strong nuclear force balance the electrostatic repulsions between the protons or does it overcome the repulsion?"

This question is not worded very well. To explain that, let us consider the simplest systems containing just two neutrons or two protons. These systems do not have bound states. That means that the reason two protons do not have a bound state is not because the protons repel each other electromagnetically (remember that strong forces are pretty much the same for protons and neutrons, so if there were a bound state for two protons, there would also be a bound state for two neutrons), but because the strong force is spin-dependent, and two protons or two neutrons cannot have the same spin projections because of the Pauli principle, and the strong force between two nucleons with the opposite projections of spins does not enable a bound state. Remember that the system containing one proton and one neutron does have a bound state (deuteron) with the same spin projections for the neutron and the proton, as these two particles are distinguishable, and the Pauli principle does not extend to their system. Let me just add that at the distance of about 1 fermi characteristic for the strong force the electromagnetic energy for two nucleons can be orders of magnitude smaller than the energy of their strong interaction.

• Hey mate, thanks for your answer. Can you please answer my main question (in bold)? – GoNK Jan 22 '19 at 4:25
• @FredWeasley : I am not sure I understand that question. Do you mean if electromagnetic force were stronger that it actually is? Then it would indeed tear apart the nucleus if it were much stronger than in reality. – akhmeteli Jan 22 '19 at 4:32
• Like if there are more protons than neutrons, that means there is a stronger electromagnetic force right? Like how does this relates to the stability of the nucleus? – GoNK Jan 22 '19 at 5:02
• @FredWeasley : Yes, it is related to stability of the nucleus, but again, it is not so much about electromagnetic force but about the Pauli principle (PM 2Ring mentioned the answers to physics.stackexchange.com/questions/323350/… ) – akhmeteli Jan 22 '19 at 5:10
• I just started nuclear physics and i dont quite get it yet. But so the imbalance between the forces cause instability of nucleus right? – GoNK Jan 22 '19 at 5:19

Neucear force obviously more stronger than electrical force but the range of strong nuclear force is about 1 fm where theoretically the range of em force is infinity.So if the size of atom is heavy(then obviously its size be big prportionally) then strong attractive force which created by neutron are not reach every corner of the neuclus which set in some limited spherical volume which radii are smaller than atomic radius...but every proton experience electrical repulsion by every other proton exits in the atom.So in this sense atom got very unstable due to electromagnetic repulsion and break off to create smaller atom where outward em repulsion may balance by nuclear strong attraction.So generally smaller size atoms are more stable than heavy atom. 