The Branches of Science PHYSICS The scientific study of matter and energy and the relations between them. CHEMISTRY • The scientific study of the structure, properties, and reactions of the chemical elements and the compounds they form. • The composition, structure, properties, and reactions of a substance. GEOLOGY • The scientific study of the origin of the Earth along with its rocks, minerals, and land forms, and of the history of the changes these have undergone. • The structure of a specific region of the Earth, including its rocks, soils, mountaines, fossils, and other features. METEOROLOGY The scientific study of the atmosphere and of atmospheric conditions, especially as they relate to weather. ASTRONOMY The scientific study of the universe and objects in it, including stars, planets, and nebulae. Astronomy deals with the position, size, motion, composition, energy, and evolution of celestial objects. Astronomers study not only visible light but also radio waves, x-rays, and other ranges of radiation that come from sources outside the Earth’s atomosphere. LIFE SCIENCE Any of several branches of science, such as biology, medicine, or ecology that studies living organisms and their organization, life processes, and relationships to each other and their environment.