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Wacky Scientist Camp Guide • Week 5

We're bringing camp home to you this summer with themed activities straight to your inbox. Enjoy a new guide each week as we explore select curriculum from each of our seven summer camps, recommended reads, and inspired videos.  Gather your materials, and let's get started...


  • Have fun!
  • Learn about chemical and physical reactions
  • Build fine motor skills
  • Practice observation expertise


We recommend safety glasses for a couple of the experiments.

  • Empty plastic bottle
  • Dry yeast
  • Liquid dish soap
  • 3% hydrogen peroxide
  • Measuring cups
  • Measuring spoons
  • Large tub or tray
  • Liquid food coloring
  • Different-shaped bottles or glasses (optional)
  • White sugar
  • Glass jar
  • Wooden skewer
  • Mentos mint candy
  • Diet Coke
  • Dull pennies
  • Salt
  • Vinegar
  • Paper towels
  • Recycled water bottle
  • Funnel 
  • Vegetable oil
  • Alka Seltzer tablets


The amount of prep work required will depend upon the age of your child.  We encourage you to have your child do as much of the work as possible.  The learning takes place through the process.

#1. Elephant Toothpaste

Sensory science

Don't worry, you do not have to brush an elephant's teeth... This chemical reaction produces a giant, smooth, and fluffy toothpaste-like consistency that is fit for an elephant, and sure to excite your littles.  Side Note:  It is not toothpaste and should be washed down the sink when you are finished.

  1. Measure 1/2 cup of hydrogen peroxide, and carefully pour it into an empty pastic bottle. 
  2. Add a big squirt of dish soap to the bottle and stir gently to mix.
  3. In a measuring cup, mix one tablespoon of yeast and three tablespoons of warm water.  Stir for about 30 seconds.  
  4. Pour the yeast mixture into the bottle then quickly step back, and watch your reaction go!  What happens?  How long does the reaction last?

Accommodations for older kids:

  • Add food coloring by stirring a few drops into the 1/2 cup of hydrogen peroxide.
  • Try the activity without the dish soap.
  • Use different shaped bottles to see how it changes the experiement.

What is happening? Hydrogen peroxide (H202) breaks down slowly and becomes oxygen (02) and water (H20).  You sped up the chemical reaction by adding a catalyst, the yeast.  The oxygen gas forms bubbles that would escape quickly, but the dish soap creates surface tension.  The bubbles get trapped and create a lot of foam.

#2. Grow Sugar Crystals

Edible science: crystal formation

  1. Dissolve 3 cups of sugar in 1 cup of boiling water.
  2. Add a few drops of food coloring and flavor, if desired.
  3. Pour the sugar solution into a jar.  Place a wooden skewer into the jar.
  4. Place the container somewhere it will not be disturbed.  You may wish to cover the jar with a paper towel or coffee filter to allow evaporation while keeping the crystal solution clean.
  5. It may take a few days to develop ideal crystal growth.  If you see crystals forming on the top of the jar, you can remove them and eat them.  If you leave them, these crystals will compete with your stick for sugar and will reduce the size of your crystals.
  6. Finally, remove your sugar crystal stick to enjoy your candy.  If you want to store before eating, keep in an airtight container so humidity in the air does not make the rock candy sticky.

Why does it work?  A supersaturated solution is unstable because it contains more solute (in this case, sugar) than can stay in the solution.  As the temperature decreases, the sugar comes out of the solution, forming crystals.  The lower the temperature, the more molecules join the sugar crystals, and that is how rock candy is created.

#3. Mentos Geysers

Create a geyser with soda and candy

  1. Open your Diet Coke bottle and place it in an area that can get dirty.
  2. Decide how you are going to put half the roll of Mentos candy in quickly.  One suggestion is to use a small test tube to stack the candies and place an index card over the opening.
  3. Drop the candies in the soda quickly.  Be prepared, the reaction will happen fast.
  4. Observe the eruption, height, trajectory, and duration.
  5. Try it again with a different size of soda or a different amount of candy.

The eruption is caused by a physical reaction rather than a chemical reaction.  The addition of the Mentos candies causes the rapid formation of expanding gas bubbles in the soda.  The expansion of the gas bubbles pushes the soda out of the bottle.

#4. Cleaning Pennies

Oxidation vs. acidic solution

  1. Collect dirty, dull, or green pennies.  This experiment will work better with pennies made before 1982.  Pennies produced before 1982 are pure copper.  After 1982, pennies are a copper and zinc alloy.
  2. Create a solution of 1/4 cup vinegar and 1 teaspoon salt.  Stir until salt is dissolved.
  3. Add the pennies.
  4. Wait 5 minutes and then place pennies on the paper towel.

How do your pennies look?  You can try the same experiment with lemon juice rather than vinegar.

It works because of a chemical reaction.  Pennies turn dull and green due to oxidation.  Over time, pennies form a layer of copper and oxygen bonded chemically on the surface of the penny.  Vinegar is an acid solution and breaks the bond formed by the copper and oxygen.  When the bond is broken then it dissolves away and combines with the acid.

#5. Lava Lamp

Groovy chemical bonds

  1. Measure 1 cup of tap water in a measuring cup.  Then add 20 drops of food coloring and stir together.  
  2. Fill the plastic bottle about 3/4 full of vegetable oil using a funnel.
  3. Pour the colored water into the plastic bottle using the funnel.
  4. Take a tab of Alka Seltzer and break it into 4 smaller pieces.  Drop the pieces in one at a time.
  5. Put the lid on your lava lamp.

The oil and water will stay separated because they cannot form chemical bonds togeher.  So once everything settles, you will always see the colored water at the bottom of the bottle, and the oil on top.  The Alka Seltzer contains sodium bicarbonate and citric acid.  When you mix these two ingredients with water, they combine to produce carbon dioxide.  The carbon dioxide creates the water bubbles that float up through the oil.  Then, as the chemical reaction slows down, the water bubbles fall back to the bottom.  

Put your thinking cap on:

Rube Goldberg's Simple Normal Humdrum School Day by Jennifer George

Kid Scientists: True Tales of Childhood from Science Superstars by David Stabler

Making with States of Matter by Anna Claybourne

Awesome Science Experiments for Kids by Crystal Chatterton


Relax with a brain-boosting video:

Good Thinking! Series by Smithsonian Science Education Center

Science Max, Science for Kids Series 

Photo credits and resources:; Scientific American; Science Notes;; Raising Lifelong Learners; Andi Anne

Gilbert House Children's Museum

116 Marion St NE Salem, OR 97301