Meltdown Showdown! Which Deicer Works Best?

In this Activity, students test two chemical deicers, rock salt (sodium chloride) and calcium chloride, to determine which melts ice better and whether it is worth the extra cost to buy a more expensive deicer. They perform three tests comparing the two deicers, predict which will be more effective at melting through a thin disk of ice, and then test their prediction. An extension to this Activity is to integrate it into a discussion about ecology. Although sodium chloride and calcium chloride are the most common deicers, they are not the most environmentally friendly.