Transcript 8.1 Electric Potential Energy and Voltage
8.1 ELECTRIC POTENTIAL ENERGY AND VOLTAGE BC Science 9: p. 270-279 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 • Electrons build up at one terminal, leaving it negatively charged and are withdrawn from the other terminal leaving it positively charged.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.