This lesson contains a “hands-on” modeling process that will enable students to produce correct chemical formulas through the manipulation of “puzzle” pieces. Because the total number of electrons donated by the cation must equal the total number of electrons accepted by the anion, matching and counting the labeled pieces will ensure the students can visualize the correct ratios within the chemical formula.
This unit includes multiple black-line masters, of many cation and anion “puzzle” pieces, best suited for reproduction on cardstock. Many of the pieces are single atom cations and anions, but this set also includes several polyatomic ions. To further the lesson, a few transition metals are also included. These pieces are designed to ensure an easy fit, and if laminated, will last for many years.
Two worksheets also accompany this unit. The first will visually reinforce the concept of electrons lost equals electrons gained, and is designed to be completed as the students construct a variety of compounds. The second worksheet is more reflective, and asks the students to answer multiple questions based on their completed work.