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In this lesson students will learn that vinegar can react with the calcium carbonate in an egg shell. First, the students will listen to the teacher read a book about eggs. The teacher will then put an egg in a jar with vinegar and leave it for two days. Students will make a prediction about what they think will happen to the egg, and then together they will investigate the final results.

Grade Level

Elementary School


By the end of this lesson, students should be able to

  • Describe the meaning of chemical change.
  • Understand that combining two substances can result in a chemical reaction/change.
  • Record observations.
  • Make a hypothesis based on their knowledge of a situation.

Chemistry Topics

This lesson supports students’ understanding of

  • Chemical Reactions
  • Chemical change
  • Observations
  • Acids & Bases


Teacher Preparation: 10 minutes

Lesson: 45 minutes for lesson, 2 days for full results


  • Raw/uncooked egg
  • Vinegar (enough to cover the egg)
  • Glass jar or bowl (large enough to hold vinegar and egg)
  • Book: Chickens Aren’t The Only Ones, by Ruth Heller


  • Always wear safety goggles when handling chemicals in the lab.
  • When working with acids, if any solution gets on students’ skin, they should immediately alert you and thoroughly flush their skin with water.
  • When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals. 
  • Students should wash their hands thoroughly before leaving the lab.

Teacher Notes

  • This lesson is appropriate for Kindergarten-Fifth grade
  • The Pre-lab questions should be discussed and answered as a class.
  • Background/results: Vinegar is an acid called acetic acid and eggshells are made up of calcium carbonate. A chemical reaction will occur between the two, and bubbles will form. These bubbles are carbon dioxide gas produced during the reaction. The other products of the reaction dissolve in the vinegar causing the shell to no longer be on the egg. The egg will still be intact due to a flexible membrane inside the shell that keeps the egg together. The egg may also be swollen due to water moving into the egg through the membrane. This membrane can be delicate so use caution when handling the egg after the shell is gone.
  • I suggest doing the following during this lesson:
    • Read the book, “Chickens Aren’t the Only Ones”, by Ruth Heller.
    • Show the students an egg and discuss its shape and strength.
    • Demonstrate that when you put an egg in the palm of your hand and squeeze the narrow ends of the egg, it doesn’t break.
    • Explain how the egg is strong because it is made from a material called calcium carbonate, the same material in seashells and a rock called limestone.
    • Put the egg in a glass jar or bowl and add enough vinegar to cover the egg.
  • Depending on the level of the students, explain that vinegar is an acid. Suggest other examples of acids to connect with student’s prior knowledge, such as the citric acid in lemons and many sodas.
  • Students will predict (introduce hypothesis here) what they think will happen to the egg shell when it sits in the acidic vinegar solution for 2 days. You may want students to write their predictions in a science journal, or use a student handout such as the one provided.
  • The provided student handout can be completed as a class activity for younger students.
  • The students can draw a “before” sketch and write initial observations for the egg, and then do the same after 2 days have passed.
  • Differentiation: You may want to have the students work in groups and each group could have their own egg to observe.
  • Optional: Students could experiment with different objects/items in the vinegar solution and compare results. Or, students could use eggs but change solutions and experiment using a soft drink or water.

For the Student

Pre-lab Questions

  1. Vinegar is an acid. What are some other examples of acids?
  2. What is a Chemical Change? Give an example.


When the egg is combined with vinegar for 2 days, I think the egg will:

A. Change Color
B. Become Hard on the inside
C. Become Rubbery
D. Not change at all


Draw a sketch of the egg on the 1st day:

Write your observations of the egg on the 1st day:

Draw a sketch of the egg after 2 days:

Write your observations of the egg after 2 days: