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? Why is a sofa soft? Answers to these questions and many more lie in the structure of matter.
Matter is made of tiny particles called atoms and molecules. They are different, depending on many things, such as: Which particles are they? How are they connected? Can they take different shapes? Can they be stronger or weaker, or change into something new? Chemistry is all about examining these particles, studying how they interact, and using that knowledge to solve problems. The goal may be to solve a crime, make new plastics, or answer questions about Earth’s past. Chemists are on the job doing all these things.
