Recently in our APC physics class we have been doing electricity and magnetism and therefore our labs include creating circuits with wires, resistors, breadboards and batteries. I believe one of the most important things I learned from this lab was that licking a 9-volt battery gives you a shock. I thank Mr. Fullerton for teaching me this trick. When you lick a 9v battery, your tongue acts as a conductor as it is wet and therefore electrons are free to move, both ends are touching your tongue and therefore a mini circuit is created. If you feel a slight shock, that's good: your battery is all charged up!