1. The problem statement, all variables and given/known data In a precipitator, at the bottom is a negatively charged wire mesh while at the top is a set of rods at the two sides that are either earthen or positively charged. The purpose of the negative wire mesh is to charge the flue ash negatively by conduction then it is attracted to the positive rods at the side. But how can the ash get the charge? Isn't it an insulator of electricity? And even if it is water present, how can it gain the charge? In a electrolysis setup, the two reactions at the cathode and anode must occur at the same time so how can the cations be reduced there? 2. Relevant equations None 3. The attempt at a solution My physics tutor said that it can transfer electron by I just don't see how. Thanks for the help!