Term | Definition |
reactant | a substance or molecule that participates in a chemical reaction |
product | a substance that forms in a chemical reaction |
chemical energy | the energy released when a chemical compound reacts to produce new compounds |
exothermic reaction | a chemical reaction in which energy is released to the surroundings as heat |
endothermic reaction | a chemical reaction that requires energy input |
chemical equation | a representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products |
mole ratio | the relative number of moles of the substances required to produce a given amount of product in a chemical reaction |
synthesis reaction | a reaction in which two or more substances combine to form a new compound |
decomposition reaction | a reaction in which a single compound breaks down to form two or more simpler substances |
combustion reaction | the oxidation reaction of an organic compound, in which heat is released |
single-displacement reaction | a reaction in which one element or radical takes the place of another element or radical in a compound |
double-displacement reaction | a reaction in which a gas, a solid precipitate, or a molecular compound forms from the apparent exchange of atoms or ions between two compounds |
free radical | an atom or a group of atoms that has one unpaired electron |
oxidation-reduction reaction | any chemical change in which one species is oxidized (loses electrons) and another species is reduced (gains electrons); also called redox reaction |
catalyst | a substance that changes the rate of a chemical reaction without being consumed or changed significantly |
enzyme | a molecule, either protein or RNA, that acts as a catalyst in biochemical reactions (241) |
substrate | a part, substance, or element that lies beneath and supports another part, substance, or element; the reactant in reactions catalyzed by enzymes |
chemical equilibrium | a state of balance in which the rate of a forward reaction equals the rate of the reverse reaction and the concentrations of products and reactants remain unchanged |