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Do you ever wonder how crystals grow? You can grow crystals right at home with some simple ingredients. Crystals are a type of material that is formed by patterns of repeating molecules that appear to have flat surfaces and facets. Crystals form when a liquid cools very slowly and/or when water evaporates from a chemical mixture leaving behind a substance whose molecules reform into new geometric shapes. Saturation happens when a mineral like salt is dissolved in water. The water can only hold a certain amount of the salt. The water is saturated when the maximum amount of salt is dissolved in it. Hot liquids can hold more substances than cold liquids.
Materials:
- Glass Cup, Jar, or Bowl
- 1/2 Cup Epsom Salt
- 1/2 Cup Hot Water
- Spoon
- Food Coloring (optional)
Procedure:
1. Prepare your hot water and pour it into your bowl.
2. If you are using food coloring add it to the hot water now. Stir until the food coloring is mixed in well.
3. Add the Epsom salt to your bowl with hot water. Stir the Epsom salt and water for at least 1 minute or until most of it is dissolved. *Not all of the salt will dissolve. We are making a saturated solution meaning the water cannot dissolve any more Epsom salt. If you don't see any extra Epsom salt, add a little more and stir again*
4. After stirring your solution, place your bowl in the refrigerator. Let your solution sit for a few hours (wait at least 3 hours for really good crystals to form!)
5. Now, it is time to check your crystals! Pour out any remaining liquid and you should be able to see your crystals clearly!
What happened? Depending on the temperature of the water, different amounts of Epsom salt will dissolve. Because we used very hot water, a lot of Epsom salt was able to dissolve. When the water cools, there is less space for the dissolved Epsom salt and some of it reforms – or crystalizes. This happens because hot water is less dense and has room for other things like dissolved Epson salt but cold water is more dense and doesn’t have room for other things.
Northern Virginia Science Center Foundation is a 501(c)(3) non-profit organization that operates the Children's Science Center Lab at Fair Oaks Mall and STEM programs traveling to schools and other community venues across the region. The Foundation is also developing the Northern Virginia Science Center in Dulles, VA, a world-class, interactive regional science center for families, students and learners of all ages made possible through a pivotal public-private partnership. Learn more about our mission today at childsci.org and our vision for the future at novasci.org.
