Pour one teaspoon of hydrogen peroxide into a small cup. Carefully observe with your eyes, ears, and - carefully - your nose. Write down everything you observe. Get ready to time the results of your next step. Add 1/8 of a teaspoon - or the smallest measuring spoon you have - of yeast to the hydrogen peroxide. Stir with a toothpick and again observe the mixture and record your observations.

Now clean and dry your cup, and get ready to start again with the same amount of peroxide, but add another dose of yeast. What do you predict will happen?

Time the new reaction, describing all the other differences as well.

Repeat steps 2 - 5 six more times (eight times total) and graph your results. After doing a quick visual evaluation of the results, move on to step 7.

Now, choose one of the other factors we have explored, and repeat the first version of the reaction, but this time prepare to change that other factor instead of concentration. What will you change, and what do you predict will be the difference from what you saw in step three? Do this version eight times total as well, and graph it.