Page 41 - Fuel Cell Teacher Edition

Gl o ss ar y

ANiON a negatively charged ion

ANODE the electrode to which electrons flow (negative terminal)

ATOM the basic unit of an element

CATiON a positively charged ion

CATHODE the electrode from which electrons flow (positive terminal)

CHEMiCAL a description of a chemical reaction in the form of an equation showing the
EQUATiON reactants and products

CHEMiCAL a state in which both reactants and products of a reaction are present at
EQUiLiBRiUM concentrations which have no further tendency to change over time; a
stable mixture of reactants and products

COEFFiCiENT a multiplicative factor in an expression, often a constant

CORRODE to damage or destroy metal by oxidation

ELECTROLYSiS using direct current to drive a chemical reaction, such as splitting water into
hydrogen and oxygen

ELECTROLYTE a liquid or gel that contains ions and can be decomposed by electrolysis

FORWARD REACTiON a chemical reaction where the reactants on the left side of the equation
react to form the product on the right side of the equation

24 TOTAL REDOX™ – FUEL CELLS TOTAL REDOX™ – FUEL CELLS 25