| A | B |
|---|
| covalent bond | the bond between hydrogen and oxygen atoms in water |
| molecule | a particle that forms when atoms share electrons |
| ion | an atom that has lost or gained electrons |
| ionic bond | the transfer of electrons between atoms forms charged ions that are attracted to one another and form |
| chemical formula | group of symbols that represents a compound |
| chemical equation | model for showing changes |
| reactants | the substances on the left of the arrow in an equation |
| products | substances on the right of the arrow in an equation |
| subscript | shows how many atoms of an element combine to form the compound |
| equations | balanced to show that atoms are neither lost nor created during a chemical reaction |
| coefficient | numeral in a chemical formula that represents the number of molecules |
| endothermic reaction | a reaction that absorbs thermal energy |
| exothermic reaction | a reaction that releases thermal energy |
| catalyst | substance that changes the rate of a chemical reaction without any change to its own structure |
| inorganic compound | a compound that does not contain carbon |
| acid | substance containing hydrogen that forms ions in water solution |
| base | substance containing hydrogen and oxygen that forms hydroxide ions in water |
| salt | compound formed from the positive metal ion of a base and the negative nonmetal ion of an acid |
| precipitate | solid substance that falls out of solution during a chemical reaction |
| organic compound | compound that has carbon in its structure |
| hydrocarbons | organic compounds that contain only carbon and hydrogen |
| crude oil | natural deposit of hydrocarbons that formed from the decay of ancient organisms under high temperatures and pressures |
| polymers | large chainlike organic molecules |
