This review worksheet not only allows students to practice writing formula units for ionic compounds, but it also includes atomic structure review. I use this worksheet as a warm-up activity with my students AFTER going over how to write formula units. The file includes the worksheet and element cards (a class set of 24) that can be laminated and reused. Once students have completed the required information for both of their elements (on the element card they receive), they have to find other classmates to "bond" with. The idea is that the students will ionically bond with other students and use both their metal and nonmetal to practice writing formula units.