6th Grade Science
                               SCHOOL'S OUT FOR SUMMER!

Enjoy your time off. Try your hand at the Density experiment below during your time off.

Rainbow in a Glass

Density is anything but dense - take advantage of this physical concept by making a rainbow in a glass. You will need:

  1. 5 glasses
  2. Sugar
  3. Water
  4. Different colored food coloring
  5. Tablespoon
  6. Epic patience and a steady hand - this will take some practice!

What to Do: Line up the glasses and put 3 tablespoons of water into the first four glasses. Add one tablespoon of sugar to glass one, two to glass two, three to glass three, four to glass four. Stir thoroughly to dissolve the sugar. Now add a different color food coloring to each glass. Pour 1/4 of glass four into glass five. That was the easy bit.

This is the tricky bit. You must pour the next layer (glass three) so gently that it doesn't mix with the first layer. You can put a teaspoon just above the first layer and pour the mixture gently over the back of the spoon to minimize splash. The more slowly you do this, the better the results. When you have filled the glass to about the same width as the last layer, repeat with glass two, and then with glass one. If you have done this right you should get something like the picture.

What's Happening? The different amounts of sugar in water create different densities of water. As you are layering them with the heaviest at the bottom, the different layers will 'sit' on top of each other. Eventually, due to particle dynamics, the layers will mix. The greater the difference in density, the longer the effect lasts. Unlike water and oil, however, once you mix the layers, they will not settle back.