there are two forces, the nuclear force which binds protons and neutrons together. However as the size of the nucleus gets larger the electrostatic force of repulsion in the nucleus overcomes the strong nuclear force. so larger atoms breakdown to form smaller atoms, why does the electrostatic force dominate the strong nuclear force. Yes, the electrostatic force will increase in strength because of the increasing number of protons, but surely wouldn't the strength of strong nuclear force increase as well????