Which of these forces are acting within a nucleus? Check all that apply.

strong nuclear force

electrostatic forces of attraction

electrostatic forces of repulsion

Answer: strong nuclear forces and electrostatic forces of repulsion

Strong nuclear force i think because the nuclear force (or nucleon-nucleon interaction or residual strong force) is a force that acts between the protons and neutrons of atoms. Neutrons and protons, both nucleons, are affected by the nuclear force almost identically.