Science Experiments for Kids

Stalactites and Stalagmites

Make your own stalactites and stalagmites.
Make your own stalactites and stalagmites.
©2007, Publications International, Ltd.

Stalactites and stalagmites grow in caves both above and underneath the ground. That process takes thousands of years, but why wait so long? With this science experiment for kids, you can make your own small 'tites and 'mites within a few days.

What You'll Need:

  • Two jars
  • Water
  • Epsom salts
  • String
  • Small weights
  • Plate

Step 1: Fill two jars with warm water.

Step 2: Mix in Epsom salts until no more will dissolve.

Step 3: Wet a piece of string, and tie a weight to each end.

Step 4: Drop one end of the string into each jar.

Step 5: Put a plate between the two jars, with the string hanging over the plate.

Step 6: Check your "cave" at least once a day to see if stalactites and stalagmites have formed.

By the way, if you're wondering which are which, try this rule: Stalactites have to hold on tight to stay on the ceiling of the cave. Stalagmites have to be mighty to stand up on the floor of the cave. Or looking at it another way, stalactites with a "c" grow down from the ceiling while stalagmites with a "g" grow up from the ground.

Eggshells are stronger than you think. Look on the next page for an experiment that shows how many phone books eggshell arcs can hold up.

For more science experiments and other fun activities and crafts, check out: