Rubber Egg: How Cavities Form

by Trish Kuffner, author of The Children's Busy Book

This science activity is great for kids who forget to brush their teeth, because it shows them how cavities form.


Chemical reactions occur inside our bodies all the time. If your child has trouble remembering to brush his teeth, this activity is a great way to show him how cavities form.

Materials

  • Egg
  • Small container
  • Vinegar
  • Chicken bone

Directions

  1. Have your child place an egg in a small container and cover it with vinegar.
  2. Set the container aside for 24 hours.
  3. Pour out the vinegar and gently pick up the egg. Squeeze it. The acid in the vinegar will have dissolved the minerals in the eggshell so that it's now soft and rubbery.
  4. Repeat the experiment with a chicken bone. In 3-4 days, the bone will be rubbery.
  5. The bacteria in your mouth produce acid that dissolves the enamel on your teeth in the same way that the acid in the vinegar dissolved the minerals in the eggshell and chicken bone. Remind your children to brush their teeth often to remove bacteria and keep their teeth healthy and strong.

Please don't delete it