Science -- Weather: Fill the cup with water. Put shaving cream on top for a cloud. Explain that when clouds get really heavy with water, it rains! Then put blue food coloring on top of the cloud, and watch it rain. Air and Weather unit
Science project: 2 clear containers, water, shaving cream, food coloring, and droppers. Slowly pour the food coloring on top of the shaving cream clouds and watch the "rain" come down when the clouds get saturated.