Activities

Gypsum Painting

Thousands of years ago, people crushed rocks and minerals to obtain colors for paints. Gypsum has been used as a white pigment. (From Mining Matters) Materials:

• 1 plastic re-sealable bag

• 1 piece white chalk

• Glue-water solution (1 tbsp. glue with 1 tbsp. water)

• Newspaper • 23 cm x 30 cm sheet black construction paper • 1 paintbrush

• 1 paper cup

• 1 plastic spoon

• Toy hammer

Instructions:

1. Put your chalk inside the plastic bag, flatten the bag to remove the extra air, and close the bag securely.

2. Place the bag in between layers of newspaper for cushioning.

3. Use a toy hammer to carefully crush the chalk into a powder.

4. Pour the chalk powder into the paper cup and add the glue solution. Mix thoroughly with a spoon.

5. Use the chalk paint and the paintbrush to create a picture on the black construction paper.

Make your own Toothpaste

From Mining Matters - Full lesson below. Materials:

• Calcium carbonate (finely powdered unflavored TUMS will work)

• Sodium bicarbonate (baking soda)

• cup and spoon to stir

• Water

• Assorted food colours and flavourings (vanilla, ketchup etc)

Instructions: The basic recipe for toothpaste is:

• ½ teaspoon calcium carbonate, ¼ teaspoon sodium bicarbonate in a small cup. Add just enough water (one drop at a time) to make a paste. Have the students taste the basic recipe and discuss possible improvements.

Extensions: • How did the homemade toothpaste compare to commercial products? • What other mineral is added to toothpaste to fight cavities? • How many of the commercial toothpastes had minerals in them? • Develop an advertising campaign for the winning toothpaste.

Eroding Escarpment

Materials

• Sand

• Soil

• Pebbles and larger rocks

• Large flat stone (like a paving stone)

• Watering can with water

Instructions Outside, build a mountain about half-a-metre high. Use as much of the materials as you like—it all depends on how big you want to make your escarpment! First, put down the sand, then spread soil on top, add the pebbles and rocks, then layer a bit more sand and soil. Because the layers of the Niagara Escarpment were laid down over a long period of time, each one was different. The last layer deposited was harder than the others. For that layer, put a large paving stone on the top of your mountain. The different layers should be visible along the sides. Plant a metre stick beside the “escarpment” and note the height of your cliff. Water and rain are major forces of erosion. These forces of nature break down the rocks and carry the debris away. With your watering can, pour “rain” on your mountain. What happens? Watch how the layers break down and note which material is carried furthest by the water. Observe your escarpment over several days. Is it getting smaller? What kinds of weather are affecting the escarpment the most? What is happening to the large paving stone on the top?