Basic Properties of Electric Charge

Having established what charge IS and how it can be produced (by conduction or induction), this section turns to three fundamental, general PROPERTIES that all electric charge obeys, no matter how it was produced or what object carries it: charge adds up algebraically like signed numbers (10.3.1), charge exists only in whole-number multiples of one smallest indivisible unit (10.3.2), and the total charge of any isolated system can never change (10.3.3) -- properties that, together with the qualitative behaviour of forces between ch …