1- Fill both of the plastic cups with 3 cm of water. In one cup put 2 mL of baking soda. Label the cup that has the baking soda "With CO2" and the cup with just water "Without CO2".

2- Add a couple drops of the liquid soap into each cup. Make sure the cups get an equal amount, do not put more than five drops, and try to avoid causing the soap to sud.

3-Use the hole punch to cut 10 leave disks from the spinach for each cup. Make sure to avoid punching out the major leaf veins.

Procedure