kemija

Kemija (chemistry) is the natural and physical science that studies matter, its properties, composition, structure, and the changes it undergoes. It seeks to understand how atoms and molecules interact, how substances are formed, transformed, and energy is involved. Kemija is often described as the central science because it connects physics, biology, and environmental sciences.

Main branches include organic chemistry (carbon-based compounds), inorganic chemistry (minerals and metals), physical chemistry (energy, kinetics, and thermodynamics), analytical chemistry (measurement and identification of substances), biochemistry (chemical processes in living organisms), and specialized fields such as medicinal chemistry, materials chemistry, and computational chemistry.

Historically, kemija grew from ancient alchemy toward modern science. Key turning points include the recognition of gaseous states, the law of conservation of mass by Lavoisier, Dalton's atomic theory, and the development of the periodic system by Mendeleev. The 20th century added quantum mechanics and spectroscopy, deepening molecular understanding.

Practice relies on careful experimentation, observation, and quantitative reasoning. Methods include synthesis and purification, titration, spectroscopy, chromatography, and crystallography. The discipline emphasizes reproducibility, safety, and ethical considerations, including environmental impact and sustainability through approaches such as green chemistry and waste minimization.

Applications of kemija span medicine, agriculture, energy, materials, and industry. Advances in chemistry underpin drug design, catalysts, polymers, sensors, and renewable energy technologies. Education typically leads to degrees in chemistry or related fields and membership in professional bodies that promote research standards and public understanding.