• Water
  • Three same-size bowls
  • Yellow, blue, green and red food coloring
  • Clear, glass dish
  • Sunshine


  1. Put two cups of water in each of three bowls that are the same size.
  2. Put a few drops of yellow, blue, green and red food color in two of the bowls. The water should look black from the mixture of colors.
  3. Cover one of the bowls of dark water with a clear glass plate or clear baking dish. The third bowl has plain water and no cover.
  4. Leave all three bowls in the sunshine for several hours.
  5. Test the temperature of the water in each bowl with your finger. Which is hottest? Why?

Science Behind the Experiment:

The dark water in the covered bowl should be the hottest. Solar energy is obtained from sunlight. The glass top allows the energy into the bowl and traps it inside. The dark-colored water, which absorbs all wavelengths of light, absorbs the solar energy and converts it into heat, causing the water to be warm.

This activity was adapted from Summer Program Tips, Strategies, and Activities for SchoolAgers 5-14 Years Old.