1.
any of the four basic forces that govern how objects or particles interact and how some particles break down.
2.
force that determines the orbits of the planets around the Sun.
3.
force responsible for the attraction and repulsion of opposite electric charges.
4.
force that holds together the protons and the neutrons.
5.
force that is present in some forms of radioactive desintegration and in the reactions that formed the Sun and other stars.