The core of understanding phases of matter is to understand the Particle Theory. This theory and its many versatile applications are explained in this book. The subject is broken down into bite-sized activities that can be performed in a classroom setting as well as by students at home. Some are quick experiments; others include observations over many weeks. All are unified by explaining how matter interacts with other matter, how phases are changed by external influences, also how all that matter matters to us. This enhanced eBook gives you the freedom to copy and paste the content of each page into the format that fits your needs. You can post lessons on your class website, make student copies, extract or rotate pages, and edit the contents of the file.