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You can easily make rock candy from a sugar solution and learn something in the process. When sugar is dissolved in water it changes size. It goes from being a grain of sugar to being a sugar molecule. This process of change is called chemistry.

Sugar grains are easy to see with the naked eyes, but molecules of sugar are not. That’s because a molecule is the smallest particle of sugar (or anything) that can exist. If it were any smaller, it wouldn’t be a sugar molecule, but something that is even tinier than sugar.

In this chemistry experiment on solutions and crystals, you are going to change sugar grains to sugar molecules. Then from the molecules, you will let the sugar reform into large crystals. In other words, rock candy!

What You Will Need For This Chemistry Lesson

About 1 1/2 cups or more of granulated sugar
1 drinking glass
A long piece of cotton string or thread
A small pot
A pencil
Measuring cups
A spoon for stirring

Pour 1 cup of cold water into a small pot and bring it to a boil. You should do this while an adult is supervising. When the water starts to boil, turn off the heat and add about 1 1/2 cups of sugar to it. Stir it with your spoon. Some of the sugar will dissolve, so you keep adding more until all the sugar is saturated but will no longer dissolve. Saturated means that it will contain all the sugar it can hold at that temperature.

Now, move the pan away from the stove and let it cool. Then pour this saturated sugar mixture into the glass. Now, tie a piece of cotton thread or thin string to your pencil and hang it all the way into the solution. Lay the pencil on top of the glass, so it holds the thread in place but doesn’t fall all the way in. Now put the glass in a cool place where it can sit undisturbed for a few days.

After the sugar solution cools, it becomes supersaturated. Crystals will begin forming on your string. After a few days, the crystals will be fairly large. At this point, you can remove the string and eat some of your rock candy. The candy is the sweet reward of a successful experiment.