Ask the students to make notes of any difficulties that they have reproducing the models from the written descriptions. When the students have completed the models have them check the reproduced models with the other group. Ask one of the groups for their descriptions and draw a graphical representation of the models on the board. Using the Organizational Chart of the Legos drawn earlier and the Periodic Table, relate the Lego model to a chemical compound. List five elements that could combine with sulfur to form chemical compounds.
Students predict and evaluate the chemical formula of neutral compounds.
Choose a couple of groups' models and graphically represent the models on the board. Discuss the structures and the possible additional structures with the students. Ask the students to predict how many Cl will combine with the ions of Ca, Al, or Si. Demonstrate the correlation to the Legos. Write AlO2 on the board and ask the students to evaluate the chemical formula.