| A | B |
|---|
| reactants | substances you start with in a chemical reaction |
| products | substances that are the result of a chemical reaction |
| chemical equation | represents what happens in a chemical reaction |
| conservation of mass | Mass is not gained or lost; the mass of reactants = mass of products |
| chemical reaction | when atoms in reactants break bonds, rearrange and form different substances in the products |
| exothermic reaction | reaction that releases heat; feels warm or hot |
| endothermic reaction | reaction that absorbs heat; feels cool or cold |
| subscript | a number written behind element symbol that shows # of atoms in the compound |
| chemcial formula | combination of chemical symbols and numbers to represent atoms in a compound |
| chemical symbol | one or two letters that represent an element (shown on periodic table) |
| balanced chemcial equation | numbers and kinds of atoms are the same on both sides of a chemical equation |
| compound | pure substance made of 2 or more kinds of atoms |
