Learning about the states of matter is a crucial part of any physical science curriculum. In this title, readers learn about the states--but also make slime, race marbles, and find out how heavy air is! Each fun experiment or activity begins with an explanation of the science concept being shown in the project. Clear step-by-step instructions guide readers through the set up and execution of the experiment. Most projects also include additional ideas to expand on the project, and some are marked as a great place to start work on a science fair project.