Strong and Weak Force

The strong and weak forces are the forces that govern the subatomic behavior of atoms.

Main Idea

The strong nuclear force governs interactions on a scale of [math]\displaystyle{ 1 fm = 10^{-15} m }[/math]. The strong force is [math]\displaystyle{ 10^{38} }[/math] times stronger than the force of gravity, and 137 times stronger than the electromagnetic force. It is the strongest of the four fundamental forces (gravity, electromagnetic force, strong nuclear force, and weak nuclear force). The strong force is what binds neutrons and protons together to create nuclei. Because it is stronger than the electromagnetic force, it allows particles with the same charge sign to be compressed together despite their revulsion due to the electromagnetic force. On an even smaller scale, the strong nuclear force is what holds quarks together. When quarks are held together, they create particles such as protons and neutrons.

The weak nuclear force, on the other hand, governs interactions on a scale of [math]\displaystyle{ 10^{-17} m }[/math]. The weak force in atoms causes radioactive decay in the atom, and is the force that allows neutrons to decay into protons, etc.