Forces of the Atom Atoms are very small particles composed of electrons, protons, and neutrons. All of these particles are held within the atom and some of these atoms require a great amount of energy to break, hence why nuclear energy is a very strong and efficient form. There are 4 fundamental forces that hold an atom together.                                         4 Fundamental Forces:                                     -Strong Force                                     -Weak Force                                     -Electromagnetic                                          Force                                     -Gravitational Force Strong Force:     The strong force is the most powerful of the four forces. It is capable of keeping small subatomic, minuscule in mass, together despite a fairly strong electromagnetic force found within the nucleus, trying to repel all of the protons away from each other. This force is caused by gluons which hold protons and neutrons together in a glue-like fashion, hence the name of the elementary particle. This attraction influenced by the  gluons can be overcome naturally when the nucleus becomes too big which leads to radioactive decay. Electromagnetic Force:     The electromagnetic force is the second most powerful force of the four fundamentals. It is the force that is experienced by negative and positive particles. Positive particles repel other positive particles while attracting negatives particles. Vice versa applies for negative particles. The atom greatly experiences the electromagnetic inside and out of the nucleus. Within the nucleus, all of the protons try repelling each other, however the strong force keeps all of the particles together. The electrons are attracted to the protons in the nucleus, usually in a 1:1 ratio, creating an evenly charged atom. Weak Force:     Weak force is third on the list. It isn't really observable in our everyday lives and is now as well known by the general population like the other three forces. The weak force is found is much more focused on in nuclear physics and is a key factor in radioactive decay as well as nuclear fission. Gravitational Force:     The gravitational force is the weakest of the 4 forces but that doesn't make it any less important. Isaac Newton observed and scientifically discovered the force of gravity in the late 1700's and many scientists have since studied it. Gravitational force is a force experienced between any objects with mass. The force is believed to be caused by gravitrons which are one of the more recently discovered elementary particles. In terms of the atom, gravitational force is felt mostly within the nucleus and between other nucleus's. Since electron's have a very small mass, they feel a very small gravitational force to the nucleus.