samira watched a demonstration in which a scientist combine two substances in a sealed container and analyze the results the endings of census did not look the same as the starting substances Samira was given a diagram with the repeating groups of atoms that make up the starting substance has less information about the properties of the starting and ending substances she created a model of the repeating groups of atoms that might make up the two ending substances that's her model correctly show why the properties of the ending substance are different from the properties show the ending substance are different from the properties of the starting substance describe what could be correct or incorrect about her model