Grades 9-12. In this guided investigation, students learn the difference between ionic, covalent, and polar covalent bonds and use electronegativity data to classify bonds by type. Students also learn to draw Lewis structures and test water solubility, melting point, and conductivity of 6 compounds to determine whether the bonds are covalent or ionic. Materials are sufficient for 32 students working in 8 groups of 4 students.