1. The problem statement, all variables and given/known data In the section on the discontinuity of the electric field (Griffiths introduction to electrodynamics) there is the following. "Where there is no surface charge, the perpendicular component of the electric field (to the surface) is continuous, as for instance at the surface of a uniformly charged solid sphere. This is as opposed to being discontinuous, by σ/ε_0 when a surface charge exists 2. Relevant equations 3. The attempt at a solution If it was a conducting sphere, I would understand that if it was neutral, there would be no net charge on the surface, but I do not see why it has to be the case here.