They also study the structure, composition, size, and history of the universe. Chemistry Chemistry studies natural and artificial substances to determine their composition and structure and the changes that occur when they combine and form other substances. Chemists take molecules apart and put them together in new ways. They try to find out why chemical reactions occur and how they can be controlled. Organic chemistry deals with most compounds containing the element carbon, and inorganic chemistry concerns all other compounds.
Radiochemistry investigates radioactive substances and their uses.
Stereochemistry examines the different chemical properties that result when compounds of the same formula differ in the relative position of their atoms in three-dimensional space. Physical chemistry studies the effects of light, heat, and other forms of energy on chemical processes. Geology Geology investigates the composition, structure, and history of the earth. Geologists analyze how such forces as earthquakes, volcanic eruptions, and wind or water erosion change the earth's surface. They also study meteorites and materials brought back from the moon.