Electrodes made from pencil lead are attached to a 9V battery to electrolyze various solutions. Oxidation occurs and the anode and reduction occurs at the cathode. When a solution of tin (II) chloride is electrolyzed tin metal and chlorine gas are produced:
SnCl2 (aq) → Sn (s) + Cl2 (g)
When a solution of copper (II) chloride is electrolyzed copper metal and chlorine gas are produced:
CuCl2 aq) → Cu (s) + Cl2 (g)
When electricity is passed through a pickle, it is conducted through Na+ and the Cl- ions that are present in the pickle. The electricity excites the electrons to a higher energy state, and when the fall back to ground state they emit a yellow/orange light.
When the balloon is rubbed on a pair of jeans, electrons are wiped from the jeans to the balloon, causing a net negative charge on the balloon. The charged balloon is held near a thin stream of water. Charges in the water rearrange so that the positive charges in the water become attracted to the negatively charged balloon, and the stream of water bends. The rearranging of charges is pronounced because water is a polar molecule.