Foaming Monsters

The girls and I are enjoying using Usborne's 100 Science Experiments as one of our science texts. Last week they made "foaming monsters."

First, they took construction paper, googly eyes (love those!) and plastic soda bottles (yes, we recycle!) to make their monsters.

After giving each monster a large drink of vinegar (to fill the bottle about halfway) and a generous squirt of dishwashing liquid, each girl added several drops of food coloring, because colored foam is even better than white!

Swirling the monster to mix the food coloring into the vinegar.

Next, we wrapped large pinches of baking soda in two squares of tissue and stuffed one into each monster's mouth.

Can you see the foam beginning
to form?

Foamtastic! This wasn't an explosion as we guessed, but a slow build. It seems the combination didn't sit too well in our monsters' tummies.

What's going on?

When you mix vinegar and baking soda, it makes carbon dioxide. The bubbles in the carbon dioxide cause the dishwashing liquid to foam so much that the solution spills out of the monster's mouth.