Top quarks or truth quarks are the heaviest known elementary particles (particles that are so small that they can not be divided). All quarks are elementary particles, and since they are fermions (which means that no two of them can exist in the same place at the same time), they have a spin of 1/2. Top quarks interact with all four of the fundamental forces, which are gravity, electromagnetism, strong force, and weak force. Almost all of the time, top quarks will decay into a bottom quark and a W boson, although it can sometimes decay into a strange quark.