Here's the steps! Give it a try for yourself!!!
6% hydrogen peroxide (I used clairoxide clear developer from a beauty supply store)
1. set plastic water bottle in pan.
2. Mix together 1 tsp. yeast and 2 tbsp. water and let set while you make the other solution!
3. Pour 1/2 cup of the developer (peroxide) into bottle, add 4-5 drops of food coloring, and then a squirt of dish soap.
4. Pour yeast into bottle and see what happens! :)
Prepare yourself for OOOOHHHHSs and AAAAHHHHHsss!!! It happens quickly but goes on for awhile! The reaction is exothermic and the bottle and foam gets warm as well.
If you want the scientific explanation: (here it is copied from the website above)
"The reaction is summarized by this formula: 2 H2O2 --> 2 H2O + 02.
Hydrogen peroxide (H2O2) naturally breaks down into water and oxygen. It is stored in opaque containers to help slow down this process. Catalase (an enzyme in all living things, including yeast) speeds up the reaction. Dish soap catches the oxygen and makes bigger bubbles and the food coloring makes it look cool. The foam and bottle feel warm because the reaction is exothermic--it releases energy as heat."