Rock Candy Crystals

Rock Candy Crystals

Here's another activity that demonstrates how chemicals change when they're combined.

Materials

• 2 1/2 cups sugar
• Button with large holes
• 1 cup water
• Pencil
• Medium saucepan
• Drinking glass or glass jar
• String

Directions

1. Help your child mix the sugar and water in the saucepan and cook the syrup over medium heat until it boils. Let it boil for 4 minutes without stirring it, then remove it from the heat and let it cool for a minute.
2. Thread the string through the button and tie it securely. Tie the other end of the string to the pencil. Leave several inches of string between the button and pencil.
3. Pour the syrup into the glass. Don't touch the glass after you?ve poured in the syrup; it will be very hot. Set the pencil across the top of the glass or jar. The button should hang suspended in the syrup.
4. When the glass is cool enough to touch, move it to a place where it'll be easy to see but be undisturbed for a week or so.
5. Look at your syrup from time to time. First you'll see small crystals forming on the string. Eventually these will become larger chunks that can be broken off and eaten.