National Chemistry Week - Experiments


National Chemistry Week - Experiments - Atoms and Molecules

It must be stressed that atoms are extraordinarily small, and although they join to form larger particles called molecules, even the molecules are so small that we still cannot see them unless we use a very special microscope. There are about 20,000,000,000,000,000,000,000,000 atoms in a glass of water.

What you will need:

different coloured gum drops (Coloured marshmallows also will do.)
toothpicks

A. Making Molecules

What to do:

Designate each colour to be a certain atom. Either write a legend on the blackboard, or have each child make an individual legend.

Example:

Yellow = hydrogen

Blue = oxygen

Green = carbon
Encourage the children to use the gum drops and toothpicks to create molecules. They may create molecules that do not exist, but that is fine.

Example:
The gum drops are the atoms
```
Hydrogen:           
Oxygen:             
Carbon:             
```
When the atoms (gumdrops) are put together, molecules are created. Below are some examples of molecules children may be familiar with.
H2O: water

CO2: carbon dioxide

O2: oxygen

CH3COOH: acetic acid

B. Making Crystals:

To make a cubic crystal such as salt (sodium chloride), you need 27 gum drops. There should be 13 of one colour and 14 of another colour. You will also need toothpicks.

Make a model of a cubic crystal as shown. Notice that there is a particular pattern in the crystal. Each side is the same shape and the same size and each side also contains the same number of atoms.

In the salt shown, each blue (sodium) atom has yellow (chlorine) atoms for neighbours, and each yellow atom has blue atoms for neighbours.

[IMAGE OF CUBIC CRYSTAL]

Matter is everything in this world that surrounds us. Everything around us is made up of extremely small particles called atoms. Atoms join with each other to form larger particles called molecules. Atoms and molecules connect to form everything outside of us and even inside of us. We, too, are made up of atoms and molecules.)

In a crystal, atoms or molecules join together in a pattern that repeats itself over and over to create a certain shape. A crystal is able to grow by adding atoms or molecules to all its sides in the exact same pattern as the atoms and molecules that were added before.

These two sections include class activities on atoms, molecules and crystals. This is sure to be enjoyed by your students.

What you will need:

A. Making Molecules

What to do:

Example:

Example:

B. Making Crystals:

Have fun!