They then provide explanations of their observations. The themes of these inquiries are revisited in detail throughout the module, giving students opportunities to re-examine and modify their explanations. In the first part of the module, Characteristic Properties of Matter, students investigate the density of solids, liquids, and gases and use density to predict the behavior of solids and liquids in a density column. They construct simple thermometers and use them to investigate the effect of heat on the density of water and air. This inquiry introduces the idea of heat as an agent of change.
Students continue by observing the changes that occur when they heat different substances.
They then investigate phase change by graphing the temperature changes in iced water as it is heated to a boil. They also investigate conservation of mass during phase change. Part I ends with a short assessment during which students use their own measurements to determine the identity of a mystery object. Students start Part II, Mixtures and Solutions, by discussing their ideas about pure substances and mixtures. They apply these ideas in an inquiry in which they determine whether samples are mixtures or pure substances.