What You Need:
- Open, outside space
- Unopened bottle of soda (20 oz., 1 liter or 2 liter)
- A large paper clip
- Roll of Wintergreen Lifesavers
To Do and Observe:
1. Bend the paperclip into a fishhook shape. Make sure that the hook can fit into the opening of the bottle.
2. Put as many Lifesavers as you can on the hook, a regular paperclip can usually hold 4-5 pieces of candy. Leave a little space at the top of the hook to hold it.
3. Open the bottle of soda, drop the Lifesaver filled hook in and step back quickly! Observe what happens when the candy and the soda meet.
What's Going On:
Have you ever felt the little bubbles in soda tickle your nose? The bubbles in the soda are made of carbon dioxide gas. That is why soda is called “carbonated”. The carbon dioxide is dissolved in the liquid. When enough gas bunches together, it forms a bubble. Usually, this happens a little bit at a time, but the Lifesavers make it happen very quickly by providing nucleation sites.
Nucleation sites are the spaces for the carbon dioxide to bunch up and form bubbles. A nucleation site can be a scratch on a surface, a speck of dust, or any place where you have a high surface area relative to volume. While a Lifesaver looks smooth, but there are lots of tiny imperfections in its surface, which allows lots and lots of bubbles to form. Plus, Lifesavers are heavy enough to sink when you drop them in, so they react to with the soda all the way to the bottom of the container. The sticky result is a fun, foaming mess.
For Younger Children
Use a bubble mixture and bubble wands to have the children make bubbles. Explain that bubbles can be any liquid or solid that has trapped air in it. Examples of are a basketball, a balloon, and our lungs (when we hold our breath). After the children have made bubbles, ask them if they have seen bubbles in their food. You can then show them the soda and have them observe the bubbles in soda. Instead of having the children dunk multiple Lifesavers, have them submerge one or two and observe what happens. An adult can demonstrate this activity with lots of Lifesavers and the children can compare the size of the messes that were made. What is the relationship between number of lifesavers and amount of bubbles?
For Older Children
This activity can be converted into a controlled experiment by trying different variables. Children can test different kinds of soda, different sized bottles, or different types of candy. Mentos ã candy also works well, but it’s a little harder to drop a lot of them into the soda bottle quickly.