Students know the common properties of salts, such as sodium chloride (NaCl).

Simple salts such as sodium chloride consist of just two different elements. They generally consist of a metal and an element from the next to last group on the right side of the periodic table (fluorine through iodine). Sodium chloride exemplifies how atoms come together to form substances that have very different properties. Sodium is a very reactive metal that bursts into flame when it contacts water. Chlorine is a poisonous, green gas. In contrast, sodium chloride is a safe, white crystalline solid. Note that other salts can be quite poisonous, so safety is not a common property of salts.

As described in the California Science Framework on page 70, salts tend to be hard and brittle, and to have high melting temperatures. Most salts dissolve readily in water, and the resulting solutions conduct electricity.