CE5_Inventory



=Introduction= In chemical changes, the molecules break apart, but the atoms never disappear. Keeping this straight requires an understanding of "atomic inventories".

=Activity= For example, if you had two carbon dioxide molecules, it would look like this: 2(CO 2 ). That is the same thing as CO 2 + CO 2. In your “atom inventory”, you would have 2 carbon atoms and 4 oxygen atoms.

We put the "Before" and "After" molecules on opposite sides of an equal sign, and look to see if they balance. For example,
 * C + O => CO 2 is not a balanced equation, because you have more oxygen on the right side than you do on the left.
 * C + O 2 => CO 2 is a balanced equation, because number of atoms matches up on both sides.