| A | B |
|---|
| Chemical change | the formation of a new substance with different properties; cannot be undone by physical means |
| Chemical equation | a representation of a chemical reaction by symbols and numbers |
| Chemical formula | a representation of a molecule or compound in which the elements are represented by their symbols and subscripts represent the number of atoms of each element |
| Chemical reaction | a change caused by the interaction of two or more substances (reactants) resulting in the formation of new substances (products) |
| Compound | a substance made of two or more elements |
| Law of conservation of mass | matter is not created or destroyed; only rearranged |
| Molecule | combined atoms of the same element (e.g., O2) |
| Precipitate | the formation of solids from a solution |
| Product | substance(s) resulting from a chemical reaction |
| Reactant | substances that are combined and changed during a chemical reaction |
| Subscript | the number written to the right and slightly below an element in a chemical formula; represents the number of atoms of an element present in a chemical formula |
