Since opposite charges attract, the negative chlorine ions collect at the positive poles to form molecular chlorine gas. The gas is dried, chilled, and pressurized or converted to liquid for storage and shipping. Chlorine is used as a building block in a range of products from laundry bleach to ski boots to leukemia medications. Introducing Building Block Chemistry Chlorine and chlorine compounds are a good way to introduce your students to building block chemistry without tackling the whole periodic table at once. On its own, chlorine has a distinct odor, although smelling chlorine is not recommended.
Liquid chlorine is amber in color.
And in low concentrations, chlorine gas is nearly invisible. But when chlorine combines with other elements it does things that will keep students tuned in. Chlorine compounds can turn blue, brown, or sparkling white. They can change odor or have none at all. They can be hot or cold.