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Teeth Eggsperiment! (0 Favorites)

LAB in Chemical Change, pH, Chemical Change. Last updated May 24, 2017.


Summary

In this lab students will observe and analyze how different drinks can stain an egg’s shell. They will then associate the results with how these drinks can stain their teeth.

Grade Level

Elementary School

Objectives

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

  • Observe and understand that there is a chemical reaction between some drinks and an eggshell.
  • Understand that different drinks can stain their teeth
  • Record and analyze results.
  • Learn the importance of brushing their teeth to maintain healthy teeth.

Chemistry Topics

This lab supports students’ understanding of

  • Chemical reaction
  • Chemical change
  • Acids

Time:

Teacher Preparation: 10 minutes

Lesson: Day 1: 1 hour and 10 minutes; Day 2: 45 minutes.

Materials

Per Group:

  • 12 eggs (not boiled)
  • 12 clear cups (big enough to fit the eggs and 6 oz. or ¾ cup of a drink)
  • 1.5 cups (12oz) of Milk
  • 1.5 cups (12oz) Dark soda
  • 1.5 cups (12oz) Red Gatorade
  • 1.5 cups (12oz) Coffee
  • 1.5 cups (12oz) Grape Juice
  • 1.5 cups (12oz) Water
  • 1 Toothbrush
  • Toothpaste
  • Crayons
  • Measuring cups (¾ cup)
  • 6 spoons
  • 12 paper plates
  • Napkins

Safety

  • Always wear safety goggles when handling chemicals in the lab.
  • Students should wash their hands thoroughly before leaving the lab.
  • Do not consume lab solutions, even if they’re otherwise edible products.
  • Food in the lab should be considered a chemical not for consumption.

Teacher Notes

  • This lab activity is designed for use in 1st grade through 5th grade classrooms.
  • A way to introduce the lab is to talk about dental health and the importance of keeping teeth clean. The lab is a demonstration of why people should take care of their teeth.
  • Students should be placed in small groups (suggested: 5-6 students per group) and work together to complete the lab.
  • The teacher should observe the groups as they pour and measure the drinks into the clear cups.
  • Explain that one egg in each of the drink samples will be left overnight to be observed the next day (6 total eggs/cups).
  • Enamel is the visible tissue of the tooth where it covers the anatomical crowning and the nerve. Enamel consists of minerals that protect the tooth. The different amounts of minerals in enamel contribute to the strength as well as the brittleness of the tooth. Enamel is avascular, meaning it has no blood flow and it is not renewable, so keeping teeth clean is vital. Drinking liquids with high acid and sugar contents, such as colas or fruit juices, should be done in moderation because staining and decay can occur. The usual color of enamel is a very light yellow to a grayish white. See NIH experiment for more information.
  • Eggshells are similar to tooth enamel. They share the same coloring, ranging from light yellow to white. The eggshell protects the egg from breaking, just as tooth enamel protects the tooth from decaying.
  • During the 30 minutes in which the eggs are submerged, the teacher can ask the class what kinds of drinks they consume and how do they think it affects their teeth.
  • For higher level or older students, you may want to use pH paper or litmus paper to determine which drinks, if any are acidic, and introduce the concept of pH and acidity as well.
  • From this lab, students will be able to see the way drinks stain egg shells which is similar to how they will stain our teeth enamel. There are drinks that stain more than others and after brushing there are some stains that were able to be removed. Also, water and milk are drinks that won’t stain our teeth. It is important that if we do drink sodas, coffee, or juices, that we brush our teeth as soon as possible to keep our enamel healthy.

For the Student

Background

Eggs are similar to our teeth as they protect the egg from breaking just like our enamel protects our teeth from decaying. It is important that we keep our teeth clean and healthy because once the enamel is gone it cannot be replaced, and our teeth can then become damaged.

Pre-lab Questions

  1. What color should healthy teeth be?
  2. What can you do to keep your teeth healthy?

Problem

How will the different drinks stain the egg shells over time?

Materials (per group)

  • 12 eggs
  • 12 clear cups
  • Milk
  • Dark soda
  • Red Gatorade
  • Coffee
  • Grape Juice
  • Water
  • Timer
  • Toothbrush
  • Toothpaste
  • Crayons
  • Measuring cup
  • 6 spoons
  • 12 Paper plates
  • Napkins

Safety

  • Always wear safety goggles when handling chemicals in the lab.
  • Wash your hands thoroughly before leaving the lab.
  • Do not consume lab solutions, even if they’re otherwise edible products.
  • Food in the lab should be considered a chemical not for consumption.

Procedure

Day 1

  1. In your group, using a measuring cup, measure 6 oz. or ¾ cup of each drink and place it in the clear cups.
  2. Repeat step 1 so that there are two cups of each drink. One cup of each drink is for the overnight observation.
  3. You may choose to label each cup, but this is optional since the drinks are different colors and it can be easy to tell which drink is in the cup based on its color.
  4. Before placing the eggs in the cups, record your observations of the eggs on your recording sheet of the “initial” for each drink.
  5. Place one egg in each of the cups (a total of 12 cups).
  6. The eggs used for the overnight observation will be put to the side; there should be a total of 6 cups, one of each type of drink.
  7. The eggs in the remaining 6 cups will be left submerged in the drink for 30 minutes (start a timer).
  8. After the 30 minutes is up, use the spoon to carefully remove the egg from each of the cups and place it on a paper plate.
  9. Record your observations on your recording sheet under the “after” for each drink. Sketch and color an egg as it appears. You should sketch and color a total of 6 eggs.
  10. Use the tooth brush and a small amount of toothpaste to brush each of the 6 eggs that have been placed on the plates. Brush for about 1 minute and gently clean off the eggs with napkins.
  11. Place the eggs back on the plate and record your observations on the “after brushing” for each drink, sketch and color the egg as you see it.
  12. After you have written down your last observations, place all the materials on a designated table so that your teacher may dispose of it later.

Day 2

  1. The 6 cups will be placed back in your groups and you will follow steps 8-12.


Observations of the egg after 30 minutes:

Drink Type

Initial

After (sketch and color egg)

After Brushing(sketch and color egg)

Milk

Soda

Red Gatorade

Coffee

Grape Juice

Water

Observations of the egg after 1 day:

Drink Type

Initial

After (sketch and color egg)

After Brushing(sketch and color egg)

Milk

Soda

Red Gatorade

Coffee

Grape Juice

Water


Analysis

  1. What drink stained the most? After brushing the eggs, was there a stain that could not be removed?
  2. Is there a drink that did not stain at all?
  3. From which eggs were you able to remove the stain the most, after the 30 minutes or overnight?
  4. After observing this lab, which drink will you prefer in the future to keep your teeth clean and healthy?