I went to class and watched this video () but I still don't understand how salt bridges work. I think I memorized all of the details and steps but I don't understand why anything is happening at all! I know that Cu2+ gains two electrons when it touches the electrode but why? And also does the electric current cause Cu2+ to go to Cu, or is it the other way around? I think the reason for my confusion is I don't get what's happening in the water in each cell. Any help would be appreciated. Also: is the salt bridge made out of the ions or does it just facilitate the motion of the ions? So is the salt bridge made out of KNO3 and KCl and NaCl or is it made out of some material that has like capillary action or something to move it?