Sahil watched a demonstration in which a scientist combined two substances in a sealed container and analyzed the results. The ending substances did not look the same as the starting substances. Sahil was given a diagram with the repeating groups of atoms that make up the starting substances, plus information about the properties of the starting and ending substances. He created a model of the repeating groups of atoms that might make up the two ending substances. Does his model correctly show why the properties of the ending substances are different from the properties of the starting substances? Describe what could be correct or incorrect about his model.