Charge conservation proof

[FrostScYthe]

Hi, does anyone know where I can find the proof for charge conservation, or another way to prove this.

The problem states:

Prove that whenever I charge a sphere and touch another uncharged sphere, the charges are distributed between them evenly.

[Tide]

If the spheres are conductors then the charge will be distributed over the pair of spheres in such a way that they end up at the same electrical potential. The charges will be equal if the spheres are the same size.