Hi everyone its my first post here, i'm an apprentice electrician and i'm having a little bit of trouble grasping the physics related to voltage, current and work done. Its probably a stupid question but here goes anyway. Using a 12v battery for example this is my understanding of voltage. A grouping of electrons (charge) builds up on the positive terminal of the battery due to a chemical process in the battery. This charge then has a larger potential to do work or push then the negative terminal? once a closed circuit with a resistor is attached the charge of electrons push's electrons all the way around the conductor through the resistor to the negative terminal. Current is basically how many electrons pass a given point in a second? Now my question is if the current is the same before and after the resistor, and the same amount of electrons are entering the resistor as coming out at the same rate. Physically, what is converting to heat and light energy given off by the resistor? Something must be changing state to produce heat and light right?