Compare current electricity to water flow, from high potential energy to low potential energy. Define electric potential in volts and the difference as voltage. Determine that to sustain the flow of charge, one end of the conductor must be kept at a higher potential energy than the other. Define electric current. Define current units as amperes, with one ampere being one 1 coulomb/sec. Indicate that a coulomb is 6.2 x 10^18 electrons. Indicate that there are no net changes as current passes through a wire