The Children’s Museum's

mission is to inspire children's creativity and stimulate their curiosity to discover the world through playful exploration of the arts and sciences.



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T: 707-546-4069
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P.O. Box 12323
Santa Rosa, CA 95406

Experiments
Adult supervision Required!

Materials:
  • Clean, dry wide mouthed glass milk or juice bottle
  • Peeled hard boiled egg that’s a little bigger than the jar’s mouth
  • Matches
  • A few strips of paper to light w/ matches

Experiment:
The object is to get the egg into the bottle without harming the egg.

  1. Start by smearing some water around the mouth of the bottle.
  2. Have the adult light a match and set the strip of paper on fire. Quickly put the burning strip into the bottle. Be careful not to accidentally burn your fingers.  
  3. Immediately cover the mouth of the bottle with the egg. In just seconds, the fire will go out, and some invisible force will literally "push" the egg into the bottle. That's amazing!

Why?
Hot air expands. Cold air contracts. When the air inside the bottle is heated, the molecules, or tiny air particles, inside the bottle spread out, increasing air pressure. As the air in the bottle cools, the air pressure decreases. The greater outside air pressure pushes the egg into the bottle. Blowing into the bottle raises the air pressure again. The air and the egg rush out of the bottle.

OK, let's get it back out. Wash the ashes out of the bottle. Turn it upside down and position the egg with the pointy end back in the opening. Take a deep breath and blow in. Continue to hold the bottle upside down, wait and watch.
Materials:
•    adult helper
•    small head of red cabbage
•    grater
•    strainer
•    2 large bowls
•    very warm water enough to cover the cabbage in a bowl
•    2 or more clear containers
•    white vinegar
•    baking soda
•    other foods to test such as lemon, soda, water, or yogurt

Experiment:
  1. Have an adult cut the cabbage in half. Coarsely grate 1 cup of cabbage into a large bowl.
  2. Pour enough warm water to barely cover the cabbage.
  3. Leave the cabbage mixture until the water turns purple.
  4. Pour the cabbage mixture into a strainer over another large bowl. Save the cabbage water in a jar for your experiments.
  5. Put ¼ cup of cabbage water into a clear container and add spoonfuls of vinegar. What color does it turn?
  6. Put ¼ cup of cabbage water into another clear container and add some baking soda, a teaspoon at a time. What color does it turn?
  7. Try testing foods and other things from your kitchen to see if they make the cabbage water change color.

Why:
The purple cabbage juice became blue-green when you added baking soda. Baking soda is a base. When you added vinegar it became pink. Vinegar is an acid. Acids and bases are a group of chemicals. Acids have certain things in common with each other while bases also have certain things in common. Acids, or foods containing acids, taste sour while bases taste bitter. Some acids and bases are too dangerous to taste so we test them in another way. You’ve made an indicator form red cabbage that tests some chemicals for us.

Experiment and info from  “Kitchen Science” by Shar Levine and Leslie Johnston
Materials:
•    adult helper to cut the lemon
•    lemon
•    2 cotton swabs or 2 paint brushes
•    paper
•    red cabbage water(from previous experiment)

Experiment:
  1. Have an adult cut the lemon in half. This is your ink.
  2. Dip the end of the cotton swab, paint brush or your finger into the “ink” and use it write a secret message or draw a picture onto a piece of paper.
  3. Let the juice dry. The paper will look blank.
  4. Take a clean cotton swab or paintbrush and dip it into some red cabbage water. Paint it over the lemon writing.

Why:
Red cabbage juice is an indicator that is used to test acids and bases. The acid in the lemon juice reacted to the cabbage juice and changed color so you could see your message.



 

Materials:

  • a package of dry beans (any kind will do)

  • a drinking glass

  • water

  • a metal cookie sheet or cake pan


Experiment:

  1. Fill the glass full of dry beans. Add enough water to fill it to the top, and place the glass in the center of the metal pan. Put it somewhere nearby, where it won't be in the way, and then go about your daily routine.

 

After a few hours, you will hear a clink as one of the beans falls out of the glass onto the pan. Then you will hear another. Over the next few hours, you will continue to hear the sounds of the beans falling, so unless you are a heavy sleeper, don't try this at night. (And of course you would never hide your experiment in your sister's closet before bedtime!) You will find that the beans expand to more than twice their original size.

Why:
Why does that happen? The dry beans absorb the water to start the process of sprouting. The water softens the cells, and is absorbed into them by the process of osmosis. This causes the cells to expand, making the beans larger.

When your experiment is finished, put the beans into some water with some spices of your choice. Then bake some corn bread, and you are ready for a tasty treat.