Published by Australian Academy of Science
Glossary | Fuelling the 21st century

anode. The negative electrode in an electrochemical cell. The anode is the source of electrons to provide electrical energy.

battery. A source of electric current. Batteries consist of two electrodes immersed in an electrolyte. The electrolyte reacts chemically with the electrodes generating an electric current. More information about batteries can be found at How batteries work (How Stuff Works, USA)

cathode. The positive electrode in an electrochemical cell. Electrons flow back into a fuel cell through the cathode.

electrode. An electrical conductor. Electrochemical reactions occur on the surface of an electrode.

An electrode can be used to deliver electricity to the body or to receive electricity from it. Delivering electricity to the body is used to stimulate; receiving electricity from the body can be used to detect and record signals. In either case the term refers to the contact formed by the stimulating or recording device within the body.

electrolyte. A substance that produces ions (particles with an electric charge) when dissolved in water. The resulting solution (which can also be referred to as an electrolyte) conducts electricity.

electron. A negatively charged particle that is a constituent of an atom. Electrons can move from atom to atom. When they do, they produce an electric current.

greenhouse gas. A gas that is transparent to incoming solar radiation and absorbs some of the longer wavelength infrared radiation (heat) that the Earth radiates back. The result is that some of the heat given off by the planet accumulates, making the surface and the lower atmosphere warmer. For more information see The greenhouse effect (CSIRO Atmospheric Research, Australia).

turbine. A device in which a stream of water or gas turns a bladed wheel, converting the kinetic energy of the fluid flow into mechanical energy available from the turbine shaft. The earliest turbines were water wheels. Now, steam turbines are driven by jets of high-temperature steam; gas turbines are driven by burning fuel vapour; and wind turbines use the power of moving air.