Thursday, March 26, 2009

GOOEY STUFF

MATERIALS

Half of a box of cornstarch (227grams)
200 ml water (7/8 cup)
Few drops food coloring
Container with airtight lid
Metal spoon

This mixture should stay fresh for about two weeks if stored in refrigerator in an airtight container.

SAFETY PRECAUTIONS
Always remind your children not to taste anything during a science experiment.

PROCEDURE

1. Mix the cornstarch and water together until texture is smooth. Add green food coloring. Have child dig into it with their hands, feeling the texture and observing the characteristics of this weird mixture.
2. Have your child describe to you the characteristics and make a list of them. They may notice it is both “runny” and “powdery” at the same time. How can that be? Encourage description and discussion.
3. Ask: What do you think will happen if you strike the “gooey stuff” with a metal spoon?


Always have the child predict what will happen, then actually do it, then discuss what they observed actually happened.


EXPLANATION

The liquid particles of the water are scattered throughout the solid particles of the cornstarch. The particles of one are dispersed throughout the other. Therefore, each substance, the liquid and the solid, retains its own individual characteristics (properties.) Hence, this “gooey stuff” has the properties of a liquid and a solid simultaneously- runny and powdery at the same time. Weird!

1 comment:

  1. This is such a cool site!! I'm so glad I found it!

    ReplyDelete