Make it Rain!
Grade Level:
4
5
6
7
8
9
10
11
12
Summary:
Students build a model mountain and observe effects of rain on Karst topography.
Materials:
sugar cubes
royal icing
eye droppers
small cups
foil pie pans
First Session:
Make icing previous to lesson. In a large bowl with electric mixer, beat whites of 3 large eggs and 1/2 teaspoon cream of tartar until frothy. With mixer on low speed, gradually beat in 1 pound confectioner's sugar until blended. Increase speed to high and beat 5 - 7 minutes until stiff glossy peaks form when beaters are lifted. Keep icing tightly covered and refrigerated until ready to use.
Each group of 4 students should have a box of sugar cubes and some icing. Direct them to build a "mountain" (can just be a large cube) cementing the sugar together with the icing and covering the outside with icing. Set them aside until the next day to dry.
Second Session:
Give each group a cup of water with food color added (blue looks best) and eye droppers. The students slowly drip water on the mountain and observe. They will soon have sink holes and "springs." The sugar will erode leaving the icing. Before it is all eroded have students gently break the mountain in two and they will see caves in the mountain.
Source:
Judy Ware and Earle Maxwell, adapted by L.J. Damron; The Educator’s Reference Desk
