unit 3c chemistry vocabulary

activation energy

smallest amount of energy required for substances to react

catalyst

a substance that speeds up a chemical reaction without permanently changing it

chemical equation

chemical formulas used as a shorthand description of a chemical reaction

chemical formula

an abbreviation that uses chemical symbols and numbers to represent a substance

chemical reaction

process by which one or more substances change to produce one or more different substances

coefficient

number placed in front of a chemical symbol or formula that balances an equation; tells how many molecules are needed

concentration

measure of the amount of one substance dissolved in another

endothermic

energy that is absorbed during a chemical reaction

exothermic

energy that is given off during a chemical reaction

inhibitor

substance that slows down or stops a chemical reaction

law of conservation of energy

energy is neither created nor destroyed

law of conservation mass

the number of atoms on the reactants side will equal the number of atoms on the products side

precipitate

a solid that is produced as a result of a chemical reaction

product

final substance formed by reactants

reactant

starting substance in a chemical equation

subscript

a number written below and to the right of a chemical symbol which tells how many atoms of that element are in the molecule