Conducting science experiments with kids at home is a great way to get them interested in science or to feed their already budding interest in science. You can do easy science for kids experiments at home with everyday, household items. And who knows? You may learn some science along the way as well!

Crystals
Crystals are solids (as opposed to liquids or gases) with repeating patterns of atoms, molecules or ions (the basic building blocks of all things). The growing of crystals is called crystallization or solidification. Crystal twins are two symmetrically identical crystals.

Some common and well-known crystals are ice, salt, diamonds, sand, quarts, and graphite. Can you think of an item you use every day at school that is made of graphite crystals? Stumped? Graphite is a kind of carbon. Have you guessed it yet? The lead in pencils is made of graphite!

Growing Salt Crystals

Materials:
· 12-16 oz Jar
· Water
· 1/2 cup of salt
· Spoon
· Scissors
· String
· 2-5 toothpicks
· Microscope (if desired) for further study

Instructions
· Fill the jar almost to the top with water
· Add half a cup of salt to the water
· Stir the water and salt with the spoon
· Continue stirring until all of the salt seems to disappear (which means it has combined with the water)
· Using the scissors, cut a piece of string slightly longer than twice the height of your jar
· Tie a toothpick to each end of the string
· Drape the string over the top of your jar so that the string falls into the water and the toothpicks hang over the outer edge of the jar
· Leave the experiment until salt crystals form on the string (usually about 1 week)

Follow-up
The crystals formed on the string are cubic salt crystals. Cubic salt crystals can be microscopic (very small) or even meters in length! Measure your crystals. How big are they? Can you find any crystal twins?

For further investigation into crystals, examine your salt crystals with a microscope. What colors do you see? What shape are your crystals? Are the crystals perfectly formed or do they have flaws? Can you find any microorganisms in the crystals?

Microorganisms are plants, animals, bacteria and fungi that are too small to see using just your eyes. You need a microscope to see them, which is how they got their name. If the water you used to form your crystals had microorganisms in it, it's possible that your crystals will as well.

The scientific study of crystals is called crystallography and people who study crystals are called crystallogists. Now that you've finished your science for kids experiment to study crystals, you too are a crystallogist!

Future Crystal Fun
Try the experiment again, this time adding food coloring to the water / salt solution. Are your crystals colored? Why or why not? Try different colors and different amounts of salt in your solution. Talk about the results with your parents or science teacher.