Final answer:
The nucleus doesn't fly apart due to the strong nuclear force, which is significantly stronger than the electrostatic repulsion and acts between protons and neutrons, maintaining nuclear stability. So the correct answer is Option B.
Step-by-step explanation:
If the nucleus is so dense and full of positively charged protons, why doesn't it fly apart due to electrostatic repulsions between protons? The reason is that the strong nuclear force keeps the nucleus together in spite of electrostatic repulsions between protons. While protons do repel each other because they all have positive charges, the strong nuclear force is an incredibly powerful force of attraction that operates at the distances found inside the nucleus. It acts between protons, between neutrons, and between protons and neutrons. This force is about 100 times stronger than the electromagnetic force responsible for the electrostatic repulsion. It also becomes very repulsive if nucleons try to occupy the same space, keeping them at a stable proximity. Therefore, the strong force is what prevents the nucleus from disintegrating under electrostatic repulsion.
Nuclear forces become extremely repulsive if nucleons (protons and neutrons) get too close, which is analogous to how ball bearings resist being pushed into one another. This characteristic ensures nucleons maintain a stable arrangement in the nucleus, contributing to nuclear stability.