A Look into the Nucleus We will answer these questions soon, but first we need to look into the nature of the nucleus and quantum mechanics.
Protons are positive and electrically repel one another.
This is called the residual strong force. Think of a nucleus as a tightly coiled spring which is the electrical repulsion, held in place by a very big rope which is the residual strong force. Even though there is a lot of stored-up energy in the spring, it can't release the energy because the rope is too strong.