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Activity Time: 60 minutes
Recommended Grades: All grades, but with parent supervision (or parent permission for teens)
Objectives: In this experiment, you will be able to observe how crystals form and grow, then have fun eating your crystals.
1. Make sure the mouth of the jar or glass you use allows a clothespin to rest across the opening without falling in.
2. Clip a wooden skewer into a clothespin.
3. Clip the skewer so that it hangs down inside the glass.
4. Make sure the skewers do not touch the sides of the jar OR each other.
5. Also, make sure the skewer stops about 1 inch from the bottom of the jar.
6. You will need to have two clothespins with skewers in each jar you set up.
7. Take out the clothespins and skewers for now and place them on the table.
8. Pour the water into the pot and boil the water on the stove.
9. Pour a cup of sugar into the boiling water and stir until it dissolves.
10. Add ½ cup of sugar at a time, waiting until each one dissolves completely before adding the next.
11. Once you have dissolved 4 cups of sugar into the boiling water, add 1 tablespoon at a time until no more sugar will dissolve in the boiling water. (You will know when this happens because the sugar will stay solid in the boiling water.)
12. Remove the pot from the heat and allow it to cool for at least 20 minutes.
13. While the pot is cooling, dip the end of the skewers NOT attached to the clothespins in the cooling sugar solution.
14. Roll this end you just dipped in the pot in some granulated sugar to help the crystals have a place to begin to form on the skewer.
15. Stand the skewer upside down with the clothespins on the bottom and let them cool.
16. Now add sugar solution to the jars you have set up.
17. Add food color to as many jars as you have set up with sugar solution.
18. Add the solution to within an inch from the top of the jar and stir the food color thoroughly.
19. Carefully add the two skewers into the jars making sure that the skewers do not touch each other or the sides and bottom of the jar.
20. Put the jars in a place where they will not be distured and where they will be able to grow over the next 7 days.
21. Observe each day as crystals form on the inside and over the open mouth of the jar. You will be able to easily break off these crystals to get the skewers out of the jar and when you want to remove crystals from the inside of the jar.
22. After 7 days, hang the skewers inside an empty jar or glass to harden.
23. If you have a magnifying glass, take an up-close look at the structure of your crystals.
The crystals result from a supersaturated solution. That means you put more sugar than water into the solution. Heating the water allows the water molecules to combine with MORE sugar molecules than they can when the water is cool. As the water evaporates over seven days, the sugar molecules arrange themselves in a geometrically constant pattern—the crystal. Also (bonus!) these crystals are tasty!
Solution - a liquid mixture in which the minor component (the solute) is uniformly distributed within the major component (the solvent)
Supersaturated solution - a solution that contains more of the dissolved material than could be dissolved by the solvent under normal circumstances.
Crystal - piece of a solid substance that has a natural geometrically regular form with symmetrically arranged planes.