Solid, liquid, and gas--these are the states of matter that young people are introduced to first. They are easily observable in everyday life. Lightning is an example of another state of matter--plasma. And there are still others, including Bose-Einstein condensates, that only exist in extreme conditions. How these states form and why they change is the focus of this engaging book, which pairs accessible information and essential science vocabulary with supporting images and diagrams. Readers will appreciate the approachable text and interesting fact boxes, which encourage their curiosity about curricular concepts.