Internet version [Naruhodo no Mori] Vol.37

by Yumiko Mori

---

Vol. 37     February 15th, 1998

Guessing Game

Home science experiments for mothers of elementary school children

Mom: "What do you think this game is?"
Tae: "Do we guess what these particles are? That's too easy. Can I use this magnifying glass?"
Mom: "Of course, you can use it."
Tae: "Look!  This is pretty! Glittering! I know this is a sugar particle."
Mom: "Good!"
Tae: "This brown one looks just like a rabbit food. Is this one from instant consomme soup ?"
Mom: "That's right!  How do you know? You rarely do cooking."
Tae: "That's a little insult, Mom!"
Tae: "This cubic shape one is a salt bit."
Mom: "Another good answer!"
Tae: "Is salt crystal always cubic?"
Mom: "Do you know this salt crystal is composed of even smaller particles and those small particles assemble themselves to from a cubic shape. I wish we could see such micro crystal. Even water is made from crystals, even though we can not see them."
Tae: "Really?"

Then Toshi and Satoshi found us.
Toshi: "Can I join?"
Satoshi: "Me, too!"
Toshi: "How about tasting this?"
Satoshi: "I want to taste too. Oh, it's very salty!"
Tae: "You are cheating! I am going to cheat too!"
Mom: "No! No! This is not a tasting experiment. I really wanted you to compare crystal shapes."

Materials

Black papers	Several
Magnifying glasses	Two	(equal in size)
A plastic tape or packing tape



Salt
Granulated sugar
Monosodium glutamate
Flour
Soup extract
Any other particles you can find in your kitchen.
	(Sugar, spices, yeast, gelatin powder etc.)

How to play 'particle guess game'

1. Put one magnifying glass over another to make 'double decker magnifying glasses'. This enhances magnifying power. You can even make 'triple decker'.
   In order to keep magnifying glasses together, use pieces of plastic tape or packing tape around the sides of the glasses.

2. Place sugar, salt, monosodium glutamate and the others on a black paper.
   Spread these particles over the paper so that each particle is clearly visible.
   (Do the preparation where your children are not around.)
   

3. Your children investigate the shape and the size of each particle with the magnifying glasses and try to identify various particles.
   

• Clean magnifying glasses well prior to the experiment. Observe particles in the brightly lit area.

• A 'double decker' magnifying glasses is more powerful. Move the glasses up and down to find the best focus.

• Salt, granulated sugar, and monosodium glutamate are crystals, which means these particles have regular shapes with surfaces in even arrangement, but flour powder is not crystal.

• When water changes to ice, water molecules are arranged hexagonal like snow crystals. This arrangement leaves some empty space, and therefore increases volume.

• An electron microscopy can visualize molecules.

   he purpose of this experiment was to give my children a chance to peek at microscopic world. Looking through a magnifier is only the beginning. If you could go more deeply into the microscopic world, you would encounter molecules, atoms, atom nucleus, and quarks. I have learned the beginning of the universe and the beginning of living organisms are related to the microscopic world. My children are still too young to learn such difficult matter. I am hoping, when they are old enough, we will be able to talk with them about molecules and atoms.

---