Fizzy Rocks

Vinegar is an acid, and when you combine it with limestone, it dissolves a little bit of calcium carbonate—releasing carbon dioxide in the form of fizzy bubbles. Allowing your kids to combine these two substances is a fun way to show them how different materials react together—and also to talk with them about different forms of matter.

Activity Instructions

Pour half a cup or so of vinegar into a glass, then drop a small piece of limestone into it. Have your child watch closely, and you should start to see the rock start to “fizz” as small bubbles are released. Then try the same experiment with a couple other types of rocks—which probably won’t create the same fizzy effect!

Materials

• Vinegar
• A Glass
• Small chunk of limestone rock (many hobby shops carry these)
• You might also collect a couple other types of rock from outside, just to show your child that not all rocks react the same way in vinegar!

Outcome

This experiment provides a fun and easy way for kids to see how different substances react together; in addition, you can use this as an opportunity to teach them about different forms of matter. Vinegar (a liquid) and limestone (a solid) combine to release a gas, carbon dioxide!