This is a great activity for any science themed birthday party and is sure to excite your guests. This is an easy to prepare experiment that is also inexpensive. Your guests will be able to create their own unique chalk bombs to enjoy outside!

Chalk bombs are fun and easy to make.


Box of colored sidewalk chalk

Dryer sheets

Rubber bands


Safety goggles for all participants

Sturdy bowl or container in which to crush the chalk


Plastic spoons

Your birthday party guests will enjoy playing with their chalk bombs outside.


Place a piece of colored chalk in the sturdy bowl.

Wearing your safety goggles, use the hammer to pulverize the chalk into a powder. Put this powder into a bowl and put a spoon with this bowl. Do this for several different colors. Set the bowls out on a table so each birthday party guests will be able to reach.

Give each guest a dryer sheet. Have each guest lay out their dryer sheet and use the spoons to add their chalk powder of choice into the center of the sheet. Each sheet should have a pile of chalk powder about the size of a golf ball.

A science themed birthday party guest enjoying chalk bombs.

Each guest now has a chalk bomb ready to enjoy outside! Pull up the edges and secure with rubber bands.