Question

A balloon is charge by rubbing and then clings to a wall.Does this mean that the wall is also charge?

Answer 1

Although the wall might be charged, even if it is uncharged the balloon will be attracted to it by the polarization of the wall material due to the electric field from the balloon. If the balloon is positively charged, the material in the wall will have its (negative) electrons somewhat attracted to the balloon, be "polarized," without current flow and there will be attraction between the balloon and the polarized material.