The potential energy between two atoms in a particular molecule has the form U(x) = 3.1 x8 − 4.8 x4 where the units of x are length and the numbers 3.1 and 4.8 have appropriate units so that U(x) has units of energy. What is the equilibrium separation of the atoms (that is the distance at which the force between the atoms is zero)?

Sorry i dont understand the question can you rephase it?

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).

Answerhund's rule;

C, small, hard spheres with insignificant volumes