When discussing about a negatively-charged solid conducting metal sphere, We agree on a statement that
like charges repel so that the negative charges (aka electrons) are evenly distributed on the surface of the sphere.
And the inner of sphere has no electric field (aka negative potential gradient). But the electrons aren't "static" though, they are moving randomly due to thermal motion. So isn't the electrons, at some very very short instance, creating an imbalance of distribution of charge of the sphere? ( like, moving to the inner centre, "clump" together with a closer distance,etc)
When we are talking about the statement, is it because we neglect the size and motion of electrons? Like, analytically, we are treating electrons distribution as a negatively-charged static infinitesimal thin gel on the surface (although the electrons are moving randomly)?