Matter, Molecules, and Atoms (Yesterday's Classics) - Bertha Morris Parker

Engaging introduction to chemical processes, starting with matter, the states it can assume (solid, liquid, gas), and how it changes from one state to another. Readers become familiar with molecules, elements, compounds, and mixtures, and how chemical changes differ from physical changes. Interspersed periodically in the text are puzzles to solve and questions to ponder that actively involve the reader.