I chose a pure gold bar to eliminate the possibility of any chemical reactions occurring, the same question would apply to any everyday object like a wooden block or a marble. Or it could apply with any two solids pushing each other.
So, when I push the gold bar with enough force, the gold bar moves away from my finger due to the pushing force from my finger, but what actually causes this force? Is it the repulsion between the outer electrons on the atoms of my skin cell membranes and the outer electrons of the gold atoms on the surface of the bar? If so, how does this happen on a wide scale to create the pushing force? And how do some of my finger prints end up on the gold bar if the two entities (the gold bar and my finger) are completely repelled by each other's electrons? How do the molecules in my skin cells end up on the outside of the giant metallic lattice that makes up the gold bar?