What two competing fundamental forces are at work inside the nucleus of an atom?

The nucleus consists of protons and neutrons.

Inside the nucleus, there is an electrostatic force of repulsion between two protons, since they are like charged particles.

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).