Before beginning this experiment, discuss carbonation with your students by letting them know that carbon dioxide gas produces the carbonation that they find when they open a can of soda. If possible, give students a small can of soda and discuss the bubbles that tickle their nose when they open the can. A good suggestion for a soda to give to children is Sprite or Sierra Mist as neither of these have any caffeine in them.
Ask students if they would like to do an experiment that’s really messy and really fun, then move on to the next section of the lesson plan.
To do this experiment students will need their toothbrush. This experiment can be done without a toothbrush, but it is more fun with one. You will also need to items listed below.
- baking soda toothpaste
- carbonated soda or water
Students would do well to wear old shirts or their craft aprons for this experiment as it can get kind of messy. Before beginning the experiment, instruct students that they will be brushing their teeth and they should remember that when they brush their teeth they should not swallow what is in their mouth. Begin the experiment by following the instructions below.
- Ask students to brush their teeth as they normally would. If students have not brought a toothbrush, it’s fine for them to use their finger to brush the paste throughout their mouth.
- When students are ready to spit out their toothpaste, ask them instead to take a sip of the carbonated water or soda.
- Ask students are taking a sip, instruct them to open their mouths and allow the foam to flow out! Make sure there is a mirror available for them to see the results of their work!
- Make sure students do not swallow the mixture. Too much of this could make them very sick.
Explain to students that the toothpaste is already designed to make bubbles as it is moved around and mixed with water or saliva. The carbon dioxide gas found in the carbonated drink causes a reaction. The result of this reaction is loads and loads of bubbles. Ask students to discuss where else they could use this information. Students will likely discuss Halloween costumes and various movies that this combination may be used in.