The potential energy of the two atoms in a diatomic molecule is defined by the Lennard-Jones potential, or U equals A over d to the twelfth minus B over d to the sixth, where A and B are positive constants and d is distance. Identify all of the following three statements that are true of this system: 1) At equilibrium, force is minimized; 2) At equilibrium, potential energy is zero; 3) At equilibrium, force is zero.