Instructions: Below you have methane (&ch4;) and oxygen (&o2;) molecules. Rearrange the atoms by clicking and dragging in the box below so that you form carbon dioxide (&co2;) and water (&h2o;). When you are done, click the "Take snapshot" button and answer the questions below.

How many &ch4; molecules did you start with?	How many &o2; molecules did you start with?	How many &co2; molecules did you make?	How many &h2o; molecules did you make?

What did you have left over? How does the balanced equation let you know how much will be left over?
Once you think you know the answer, go to the next step.