Here's an upgrade to the desperate need for chemistry students to identify elements and compounds and write their formulas with yet another worksheet. This activity lets students work in pairs to identify 18 materials as monatomic or diatomic elements, acids, ionic or covalent compounds and then name them. You can use it for practice or as a quiz.
Students teach each other the things they've missed or don't understand and you only have to monitor their work. A key is included. This is also a good review the day you begin balancing reactions.
This takes about 15-20 minutes and students enjoy it.
Keywords: stoichiometry, moles, Avogadro's number, molecules, atoms, particles, ionic, covalent, metallic, elements, periodic table, atoms, non-metals, gases, solids, liquids.