Growing crystals of salt and sugar is a very educational craft

Here is what the scientist taught Mimi, McAveler, Brad, and Paul about growing crystals.

Kids, sometimes are formed by cooling a melted or vaporized solid. Diamonds are formed in this way.

When you buy table salt, you are purchasing millions of tiny crystals of sodium chloride. But because they have been knocked around during processing, handling, and shipping, you cannot see the crystals' true beauty, even with a magnifying glass.

Every chemical forms its own type and shape of crystals. Crystals of salt are cubes--perfect little squares! Crystals are a very pure form of the chemical.

Here's what you will need for growing crystals

Salt

Sugar

Two tall, clear glasses

Short length of clean, white string

Pencil





Clean metal weight like a paper clip or a washer

Spoon and fork for stirring

Boiling water--only your parent or teacher can handle boiling water

Aluminum foil

Frying pan

Wooden spoon

Stove with an exhaust fan over the stove

Let's make rock candy crystals!

Ask your parent or teacher to boil some water. Fill a tall glass right to the brim with sugar. Slowly pour boiling water into this glass. The sugar will sink. Use a fork or spoon to dig into the sugar, right to the bottom of the glass, to wet all of the sugar. Add more boiling water until the glass is almost, but not quite, full. Stir the glass a few minutes to dissolve the sugar.

Tie your small weight to the end of the string. Tie the other end of the string around the pencil and then roll the string around the pencil until your weight will almost touch the bottom of the glass. Drop the string and weight into the glass, supported by the pencil.

Set this arrangement aside, uncovered, in a warm place where it will not be disturbed for several days. Watch the crystals grow on the string. You are growing crystals and making

Crystals will eventually form a crust on the surface. Break up this crust so more water can evaporate. As more water evaporates, more and more crystals will be forced out of solution and will grow in your glass. This process is called crystallization.

Growing crystals of salt--beautiful little cubes

Fill two glasses half full of salt. Add enough water to almost fill both glasses and stir well for a few minutes. Allow the excess salt to fall to the bottom.

Both glasses now contain a saturated solution of salt. This means that the water cannot hold any more salt in solution. If any water evaporates, more salt will be forced out of solution as crystals.

Prepare your string and weight just like in the experiment with the sugar and place it in one glass of salt solution. Cover the second glass with a piece of aluminum foil and use it as a reservoir of salt solution.

As water evaporates from the glass with the string in it and crystals form on the string, add more salt solution from the reservoir. Continue to do this for several weeks and watch the crystals grow quite large. You will have clusters of beautiful cubical crystals that will be large enough to be appreciated through a magnifying glass.

Let's change a crystal into a liquid

WARNING: KIDS, THIS EXPERIMENT CAN ONLY BE DONE WITH YOUR PARENT OR TEACHER. DO NOT TRY IT ON YOUR OWN.

Ask your parent or teacher to put a cup of sugar into a dry frying pan and to turn on the heat. Stir slowly until the sugar begins to melt. Turn the heat down a little and continue to stir until all the sugar melts--until all the white sugar disappears.

Turn the heat down low and wait until the brown liquid begins to boil and becomes dark brown. You have changed solid crystals into a liquid! This process is called caramelization. Caramel is used in manufactured foods like Root Beer and Coke.

The caramel is VERY HOT, even hotter than boiling water. Allow it to cool. Ask you parent or teacher to add some water and to make sure it is cool enough to taste. Taste the caramel. Is it sweet like candy?

Clean up your experiment by allowing the pan and utensil to soak in water for ten minutes. Everything will dissolve and rinse off easily!


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