Materials Required:
l Knife
l Cooked spaghetti
l Fish bowl
l 1 cup vinegar
l 1 cup water
l Red and blue food colouring
l 2 tablespoons baking soda
The help of one of your parents
Procedure:
- The next time you have spaghetti for dinner, ask one of your parents to cut a few strands of the cooked spaghetti into 1 to 2½-inch pieces.
- In a fish bowl or other large container, mix the cup of vinegar and the cup of water. Then add a few drops of red and blue food colouring. Slowly add the 2 tablespoons of baking soda.
- Now drop the pieces of cooked spaghetti into the bowl. Purple worms will waggle back and forth, but some will rise to the top and fall to the bottom of the container several times. Can you explain why?
This Is What Happens:
The vinegar and baking soda form gas bubbles, which collect on the spaghetti. Because the gas bubbles make the spaghetti lighter, the pieces rise and drift in the solution. The gas bubbles of those pieces that rise to the top of the container break open at the surface, causing the pieces to fall to the bottom, where more gas bubbles collect on the spaghetti, and the process is repeated.
