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MAKING GLASS FROM SCRATCH
Materials Needed
- 1 cup of sugar
- ¼ cup water
- Hot plate and sauce pan or hot pot (to boil water)
- 8-inch square sheet of glass or a cookie sheet
- Newspaper
- Assorted glass objects
Step 1:
Begin the glassmaking exercise by heating the water. You are going to make “pretend” glass using sugar in place of the actual raw material, sand. Examine the sugar and describe it in terms of its color, texture, and shape. Note the similarities between the sugar and sand. Describe the water and how it changes as the heat begins to make the water boil (e.g., after the sugar has melted it will look like a brown liquid). Note the heat energy involved in making the water boil as well as the steam that is produced. Next, pour the sugar into the boiling water. Pretend the sugar is sand (minerals) from the ground.
Step 2:
Stir the mixture vigorously over the heat until the sugar is dissolved (about 5 minutes). Describe the changes in the sugar and water. Note that this is how glass looks before it cools.
Step 3:
Put several layers of newspaper under a sheet of glass or a cookie sheet. (If you are worried about handling glass, use a cookie sheet – although you will not be able to see through it.) Carefully pour the mixture onto the sheet of glass and allow it to cool (about 15 minutes).
Step 4:
Hold up the sheet of “glass” so you can see through it. By allowing it to set overnight, the “glass” will become frosted. The next day, describe the changes that occurred overnight and why (e.g., the water evaporated leaving sugar crystals behind).
Step 5:
As an optional exercise, illustrate glass recycling by scraping the dried “glass” back into the pan (pretending it is small pieces of crushed, recycled glass), adding water, and reboiling the mixture. More sugar will need to be added to repeat the procedure. Try and figure out which resources were replaced when the crushed glass was used to make the new glass (minerals, energy).
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