In a voltaic cell, why do electrons flow at all? If I place a piece of zinc metal into a zinc ion solution, nothing happens, right? Likewise if I place a copper electrode into a copper ion solution, nothing happens. When I attach the half cells with something that allows electrons to flow through it, then you get voltage from the electrons of the zinc going to the copper electrode and the copper ions becoming attracted to the electrons. (This is assuming I've attached a salt bridge as well). My questions is: why does attaching something that allows for the flow of electrons actually mean that any electrons will flow? Why doesn't the zinc half cell and the copper half cell just sit there and nothing happens? The electrons can't be attracted enough to the copper to flow through a wire just to get to the copper ions, can they? I'm a bit confused. Any help would be great!