The Strong Force in Atomic Mechanics

There's no significant long range interaction between different nuclei. And the electrons don't feel the strong force at all. It soon became clear that protons and neutrons could not be regarded as elementary particles. They have internal structure. So they don't know base simple equations. That was one thing that came clear. The other another thing is that protons are representative of a much larger family of particles called hadrons that also exhibit the strong interaction, but they're unstable.