keemiateaduse

Keemiateadus, or chemistry, is the branch of science that studies matter: its composition, structure, properties, and the changes it undergoes. It seeks to understand how atoms combine into molecules and how chemical reactions transform substances, producing new materials and energy changes.

Chemistry is traditionally divided into several core fields: organic chemistry (carbon-based compounds), inorganic chemistry (non-organic substances), physical chemistry (theoretical and mechanistic aspects), analytical chemistry (identification and quantification of substances), biochemistry (chemical processes in living organisms), and materials chemistry (design of materials with desired properties). Interdisciplinary areas include chemical engineering, environmental chemistry, and medicinal chemistry.

Scientists use experimental techniques such as spectroscopy, chromatography, crystallography, and electrochemical methods, along with computational modeling and simulations, to characterize substances and study reactions.

Historically, chemistry evolved from practical alchemy toward a rigorous science in the 17th–19th centuries, leading to the development of the law of conservation of mass, the concept of elements, and the periodic table. Key milestones include Dalton's atomic theory, Avogadro's hypothesis, and Mendeleev's periodic table.

Chemistry underpins many sectors, including pharmaceuticals, agriculture, energy, materials, and environmental science. It provides tools to develop new drugs, polymers, catalysts, and sustainable processes, and it informs safety, regulation, and policy related to chemical hazards.