"Strike It Rich" Lab Results

This lab was meant show students the surfaces of metals can be changed.  Each group brought in 3 shiny pennies (they were cleaned with steel wool if needed).  Two of the pennies were placed a solution of solid zinc and zinc chloride solution and slowly boiled for 2-3 minutes.  The pennies were rinsed with water and one was placed in a bunsen burner flame for 10-20 seconds.  The three pennies were then compared side by side.  Picture below from 2007-2008 school year.