Floating Balls

Hand holding dropper for an experiment at day care

This activity promotes development and learning by encouraging children to observe, explore, and describe the principles of water and oil. This simple act of observing, wondering, asking questions, and finding solutions forms the basis for children’s later scientific learning.

Materials Needed:

  • ½ Cup water
  • ½ Cup vegetable oil
  • Glass or jar
  • Blue or green food coloring
  • Eyedropper

Participants: This activity is intended for adult/child interaction.


  1. Pour the water into the glass or jar. Slowly add the vegetable oil.
  2. Add four or five drops of food coloring to the jar with the eyedropper.
  3. Ask your child to observe the liquids in the glass. What is happening to them? Notice that the oil floats on top of the water and the balls of food coloring sit just beneath the oil’s surface. This is because oil and water are immiscible, meaning they don’t mix and will separate into layers.
  4. Use a pencil or the edge of a spoon to gently push the balls of food coloring into the water.
  5. Observe and record your findings.
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Bright Horizons
Bright Horizons
In 1986, our founders saw that child care was an enormous obstacle for working parents. On-site centers became one way we responded to help employees – and organizations -- work better. Today we offer child care, elder care, and help for education and careers -- tools used by more than 1,000 of the world’s top employers and that power many of the world's best brands
Hand holding dropper for an experiment at day care