Go Nuts!

Here's a quick way to make delicious sugar-coated nuts, while learning something about sugar's phases. A phase is a physical state of matter - you probably know the terms solid, liquid, and gas. We're used to thinking of sugar as a solid. When you dissolve it in a liquid, like coffee, tea, or milk, the sugar molecules break up and float around in the liquid. But that's not really the same as liquid sugar, which would be a liquid that is made up of pure sugar. We can usually make a liquid from a solid by heating the solid up, thereby melting it. You're familiar with the way that ice melts - well, you can do the same thing with sugar. It just needs to be heated to a very high temperature, 365^oF.

What you'll need:
1/2 cup table sugar (sucrose)
1 cup nuts (peanuts, walnuts, almonds, or whatever you like)
Metal saucepan
Spoon
Stove
Magnifying glass

Look at the sugar crystals with a magnifying glass. What do they look like? Put the sugar into the saucepan and heat on low-to-medium until the sugar melts. Keep stirring to help the sugar melt evenly. Scrape the sides of the pan, and try to prevent the sugar from turning brown. When the sugar is all melted and has started to boil, remove the pan from the heat. Add the nuts quickly and stir to coat. Let the sugar-coated nuts cool for at least 30 minutes. Be very careful when doing this experiment because you can get burned by the hot sugar. Have an adult help you. Before you eat the nuts, look at the sugar coating with a magnifying glass again. Does the sugar look the same?

Before melting, the sugar looks like tiny, perfect cubes. These are sugar crystals. But after it have been melted and cooled, the sugar doesn't look so perfect. When a liquid is cooled pretty quickly, the molecules don't have time to organize themselves into perfect crystals, and so they look irregular. In the next experiment, you'll make rock candy, which has beautiful sugar crystals. But they will take a long time to form!