What's the role of the strong nuclear force in nuclei stability?

The strong nuclear force holds the protons and neutrons together in the nucleus, providing stability against repulsive electromagnetic forces.

The strong nuclear force, also known as the strong interaction, is one of the four fundamental forces of nature. It is the force that binds protons and neutrons together in atomic nuclei. This force is essential for the stability of the nucleus, as it counteracts the electromagnetic force that would otherwise cause the protons, which are all positively charged, to repel each other and break the nucleus apart.

The strong nuclear force is about 100 times stronger than the electromagnetic force, but it operates over a very short range. It is effective only within the nucleus of an atom, typically up to distances of about 1 femtometre (1 fm, which is 10^-15 metres). Beyond this range, the strong force rapidly diminishes and becomes negligible, which is why it doesn't affect the structure of the atom beyond the nucleus.

The strong nuclear force is also responsible for the binding energy that holds the nucleus together. This energy is equivalent to the mass defect of the nucleus, which is the difference between the mass of the nucleus and the sum of the masses of its individual protons and neutrons. This mass defect is converted into energy according to Einstein's famous equation E=mc^2, where E is energy, m is mass, and c is the speed of light. This energy is what keeps the nucleus stable and prevents it from falling apart.

In summary, the strong nuclear force plays a crucial role in the stability of atomic nuclei. It binds protons and neutrons together, counteracts the repulsive electromagnetic force between protons, and provides the binding energy that holds the nucleus together. Without the strong nuclear force, atomic nuclei would not be stable, and atoms as we know them would not exist.