1. Review for the quiz. Ask your students if they remember the three facts about atoms and molecules they learned in the previous activity: atoms last forever (except in nuclear changes), atoms make up the mass of all materials, and atoms are bonded to other atoms in molecules. 2. Have students take the quiz. Pass out one copy of the 2.4 Atoms and Molecules Quiz to each student and give them 10-20 minutes to take the quiz. Tell students that they will be graded for their answers on this quiz. 3. Discuss their answers to the quiz. Ask students to partner or divide into groups and share what they thought were the best answers to each question. Give the students feedback on areas of the quiz that were difficult to them. 4. Introduce the Molecule 11 x 17 Poster. Post one copy of the Molecule 11 x 17 Poster on the wall. Tell students that they can use this as a reference in future lessons if they are having trouble remembering the difference between an atom and a molecule.