Experiments: Sink or Float?

What Kids Learn

This experiment helps kids learn the concepts of density and flotation. Most kids would probably guess that candy will sink in water because it looks heavier. But if something is less dense than water, it will float. Hershey Kisses will sink, but a 3 Musketeers bar will not. Why not? The nougat contains trapped air bubbles, so it's less dense than water.

How to Play

Check with parents before doing this experiment. Some kids have food allergies, so they may be allergic to certain candies. Ask parents which candies are OK to use.  

candy experiments: sink or float small

Explain to the kids that density is how much stuff is packed into the same amount of space. (For example, if you compared a cup of honey and a cup of water, the gloopy, thick honey would be more dense than the water.) 

So some things float on water while others sink. Follow the instructions below to find the density of different candies. Which ones float and which ones sink? See if the kids can guess why.

What you need:

  • Various candies, such as 3 Musketeers bars, Kit Kat bars, marshmallows, chocolate kisses, chocolate pretzels, hard candies, conversation hearts, candy corn, and gummi bears
  • Cups or bowls of water

What to do:

  1. Have kids drop the candy in the water.
  2. Watch what happens: Does it sink or float?
  3. If you have a 3 Musketeers bar, poke it to break the chocolate shell. Do you see bubbles escaping?

© Loralee Leavitt. Used with permission.
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Reviewed by: Mary L. Gavin, MD
Date reviewed: January 2011

Kids Health

Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.

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