The strong nuclear force is one of the four fundamental forces of nature and is responsible for binding protons and neutrons together in an atom’s nucleus. It is the strongest of all fundamental forces, but it acts over an extremely short range—only about 1 to 3 femtometers (1 femtometer = 10⁻¹⁵ meters).

Despite the electrostatic repulsion between positively charged protons, the strong nuclear force holds them together, along with neutrons, to form a stable nucleus. This force is attractive at short distances but becomes repulsive if nucleons get too close, maintaining the optimal spacing in the nucleus.

Key roles of the strong nuclear force:

• Stabilizing atomic nuclei
• Driving nuclear reactions, including fission and fusion
• Governing the structure of atomic nuclei and subatomic particles

Without the strong nuclear force, atoms could not exist, and matter as we know it would fall apart. It is the foundation of nuclear physics and essential to the energy released by stars and nuclear power.