Chemistry is a class subject that focuses on the study of matter and its properties. It involves the study of atoms, molecules, and their interactions with each other. The term 'ATOM' refers to the smallest unit of matter that can exist in isolation. Chemistry classes cover topics such as chemical reactions, thermodynamics, and the structure of matter. Students learn about the different elements and how they interact with one another. They also explore the properties of matter, including its physical and chemical properties.