Part liquid, part solid

Globule wonders...

What is a liquid? What is a solid?

Experiment: Part liquid, part solid

Hypotheses: Present children with the two questions. If they have difficulty answering, ask them more precise questions. Ask them if water is a liquid or a solid. How do we differentiate a liquid from a solid?

Examples of responses:
A solid is hard. A liquid is soft.
Our finger can penetrate a liquid but not a solid.
Solids can be held in our hands but liquids require containers.

Material:

• 1/3 cup of cornstarch per child
• 4 to 5 tablespoons of water per child
• Food colouring
• Popsicle sticks
• 1 "Ziploc" bag (optional) 

Manipulations:

1. Put an apron on before you begin.
   
   
2. Your daycare worker will give you a bowl containing 1/3 cup of cornstarch and a glass containing 3 tablespoons of water.
   
   
3. Add a drop of food colouring to the water and stir with a popsicle stick.
   
   
4. Pour the water into the cornstarch and mix until a paste is formed.
   
   
5. Plunge your hands into the mixture.
   
   
6. Gently try to push your finger through the mixture. You will easily succeed!
   
   
7. Try to form a ball with the mixture.
   
   
8. Squeeze the mixture between your fingers.

Alternative 1:
To limit messes or for younger children for whom stirring is difficult, place the cornstarch, water, and food colouring in a "Ziploc" bag. They can remove the mixture from the bag when they are done kneading it.

Alternative 2:
Make one large recipe if you wish to simply demonstrate the experiment. Give children a chance to experiment one at a time.

Explanations: The mixture obtained was part solid, part liquid. It had certain liquid properties and certain solid properties. This can be explained by the fact that cornstarch does not dissolve in water like sugar or salt. Cornstarch particles remain in suspension in the water. They roll on top of each other. Water travels between the cornstarch particles and it therefore escapes when you squeeze the mixture in your hand.

Angélique Boissonneault

has a Bachelor's Degree in Biological Science. She has worked in a laboratory and tested her knowledge. She has taught Math, Chemistry, and Physics. She has also developed a simplistic and innovative approach designed to introduce young children to scientific experiments, old and new. She created her friend Globule. This character is sometimes red, and sometimes white. He guides little ones through their scientific experiments and discoveries. It is clear to see Angélique is passionate about children and science. Globule's Approach.