Rock On--Fizzy Fun

YOU WILL NEED

  • Vinegar
  • Glass
  • Small chunk of limestone rock
  • Several different rock types

HERE'S HOW

Pour a half cup of vinegar into a glass. Add a small chunk of limestone rock. (Find limestone outside using a rock identification book or buy a piece at a hobby shop). Watch closely. After a few minutes the rock will start to fizz. Now try the same test with other rocks and minerals. You may not see any bubbles.

WHY?


Vinegar, an acid, dissolves bits of a material called calcium carbonate in the limestone. This releases carbon dioxide, a gas that rises to the surface as a stream of bubbles. Rocks that don't contain calcium carbonate won't fizz.

Text by David George Gordon
Illustration by David Bamundo

Illustration: a boy looking at a glass holding a rock
Fizzy Fun