What differentiates Ionic and Covalent compounds?
Ionic Compounds are Salt Crystals
Ionic compounds dissolve in water. We take advantage of this property all of the time. For example, when you "salt" your food, what you taste are the ions that dissolved into your food and are now touching taste receptors on your tongue. If the salt did not dissolve atop of your food, then you will feel it dissolve on your tongue. In the intermolecular forces section, we will look at how we are able to smell molecules that are floating through the air.
When ionic compounds are not dissolved in water, they form crystals. If you want to see some amazing crystals, find some aqueous copper sulfate and let the water evaporate. I think you can get copper sulfate at a hardware store or a gardening store because it is used as an organic pesticide. If it has not already been dissolved in water, you can enjoy its crystaline shape when you buy it. To get really big crystals, though, dissolve it in water and let it dehydrate very slowly over time. This image is supposed to give students the idea that the crystals are made up of alternating positive and negative ions. The ions are attracted to each other and therefore they will organize themselves into the most compact shape they can, a crystal.
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