What would be the interaction forces between two copper spheres each of mass 1g separated by a distance of 1m, if the total electronic charge in them differed from the total charge of the nuclei by one percent?

There will be two types of mutual interactions between the copper spheres namely a gravitational attraction and an electrostatic repulsion. But as we know already, the gravitational force of attraction will be several orders weaker than the electrostic force of repulsion, therefore we can simply neglect the gravitational influence here. Thus, the numerical is based on just a simple application of the Coulomb's Law. The calculations will go as further :

Therefore the two copper spheres will repel each other by a force of magnitude approximately equal to 1.74 × 10¹⁵ N.