Chemistry is the science of how matter transforms from starting materials into other substances. Driven by physics and the fundamental properties of the elements, chemistry frees us from depending on the materials we find in nature, and enables us to invent our own. In this course, you'll learn the fundamentals of chemistry from the perspective of reactions. Forgoing the usual approach based on quantum mechanics, you'll work through puzzles and patterns to see how charge, energy, and probability combine to determine the basic behavior of molecules undergoing chemical reaction. By the end, you'll be able to make predictions about simple chemical systems and will be ready to take on the next step, the chemical bond.