Why does the strong force hold atomic nuclei together despite proton repulsion?
The atomic nucleus remains intact because of the strong force, which acts as a powerful counterforce to the intense electrostatic repulsion between positively charged protons.12
While the electromagnetic force causes protons to repel one another, the strong forceāthe most powerful of the four fundamental interactionsāoperates at short range to bind protons and neutrons together. This force is effective only within nuclear distances of approximately meters, which is roughly the diameter of a proton.324
At the subatomic level, the strong force is governed by quantum chromodynamics, where quarks within nucleons exchange massless gauge bosons called gluons. The residual effects of these interactions between quarks are what ultimately bind the nucleons into a stable nucleus, overcoming the repulsive electrical forces that would otherwise drive the protons apart.42