| A | B |
|---|
| Element | a pure chemical substance consisting of one type of atom distinguished by its atomic number |
| Atom | Smallest particle of matter |
| Molecule | 2 or more atoms that are connected to each other |
| Chemical reaction | A change that rearranges the chemical composition of matter, evidence can be: smoke or gas produced, color change, odor change, formation of a precipitate, temperature change |
| Chemical formula | A way of writing out a chemical to show what atoms make it, H2O or 3HSO4 |
| Chemical Equation | CH4 + 2 O2 CO2 + 2 H2O , written expression of chemical reaction, showing reactants and products. Chemical equations are “balanced”. This means there are the same type and amount of atoms at the beginning and at the end of the equations. This demonstrates the Law of Conservations of Mass. |
| Reactants | The chemicals before a chemical reaction |
| Products | The new chemicals after a chemical reaction |
| Law of Conservation of Mass | Matter can NOT be created or destroyed, it can only change forms. Chemical equations demonstrate this by being perfectly balanced (same number and types of atoms are on both sides, just in different molecules) |
