8.1 ELECTRIC POTENTIAL ENERGY AND VOLTAGE BC Science 9: p

Energy Energy is the ability to do work or to make things move or change. Energy can be stored in electric charges within batteries so that it can be used later to do work.

Electrochemical Cells Electrochemical cells convert chemical energy into electrical energy. Connecting electrochemical cells together creates batteries. The ends of the batteries are known as terminals. – Connecting the terminals allows electrons to flow from the battery through a device that converts electric energy into different forms of energy (ie. heat, light, sound).

Electrochemical Cells A battery provides energy to push negative charges (ie. electrons) through conductors. A battery has two terminals called electrodes. – One terminal is positively charged the other is negatively charged.

Electrochemical Cells A battery’s electrochemical cells can be wet cells or dry cells. – In dry cells, the electrolyte is a moist paste. – In wet cells, the electrolyte is a fluid. Electrons build up at one terminal, leaving it negatively charged and are withdrawn from the other terminal leaving it positively charged.

Electrochemical Cells

Electric Potential Energy Electric energy can do work. Electric energy that is stored is potential energy. When energy is moving, it is known as kinetic energy. The amount of electric potential energy per coulomb of charge is called the potential difference (ie. voltage). Extra electrons will move to a location where there are less of them.

Producing Voltage Electrodes in an electrolyte chemically react to produce electrons. Different charges are created on each electrode. This difference in charge is called potential difference (ie. voltage).

Measuring Voltage Voltage is measured in volts (V). A voltmeter is a device that measures the amount of potential difference (ie. voltage) between two locations of charge separation.