Chemical Reactions, Chapter 9

Terms in this set (15)

chemical reaction
the process by which one or more substances rearrange to produce one or more different substances
chemical equation
a way to describe a chemical reaction using chemical formulas and element symbols
reactants
A starting material in a chemical reaction
product
A substance produced in a chemical reaction
law of conservation of mass
states that the total mass of the reactants before a chemical reaction is the same as the total mass of the products after the chemical reaction.
Coefficient
A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.
Activation Energy
the minimum amount of energy required to start a chemical reaction
Physical Change
A change in a substance that does not involve a change in the identity of the substance
Chemical Change
A change that occurs when one or more substances change into entirely new substances with different properties.
endothermic reaction
A reaction that ABSORBS energy in the form of heat, and gives off cold
exothermic reaction
A reaction that releases energy in the form of heat
catalyst
substance that speeds up the rate of a chemical reaction
enzyme
is a catalyst that speeds up a chemical reaction in living cells
inhibitor
A substance that slows down or stops a chemical reaction
temperature
A measure of the average energy of motion of the particles of a substance.
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