Look around. You might see a book, a sofa, your fingers. You might see a glass of water.
Perhaps you can spot trees or rocks through a window. You can definitely feel air fill your lungs. These things—and everything else in the world—are made up of matter. But why is a rock solid, while air is a gas? Why is your fingernail hard but bendable? Why is water fluid, and why is a cloth-covered sofa soft? Answers to these questions and many more lie in the structure of matter.
Matter is made up of tiny particles known as atoms and molecules. They are different, depending on many things. Which particles are they? How are they connected? Can they take different shapes, be stronger or weaker, or change into something new? Examining these particles, studying how they interact, and using this knowledge to solve problems—that is chemistry. Whether the goal is to get to the bottom of a crime, develop new plastics and sports fabrics, or answer questions about Earth’s past, chemists are on the job.
