Gravity is the weakest of the four forces. It is so weak that if it were not for the fact that it can act over long distances and is always an attractive force, we’d never notice it. Every particle in the universe feels the force of gravity. | The second strongest of the four forces, it is the union of electricity and magnetism. This force interacts only with charged particles like electrons and quarks, and is much stronger than gravity. | The strongest of the four forces, with the shortest range of all. It holds the quarks together in the protons and neutrons, and holds protons and neutrons together to form the nuclei of atoms. | The second weakest of the four forces, it has a very short range. The weak force affects all matter particles, but not force-carrying particles. It is responsible for radioactive decay in nature. |