dalton

Dalton is a surname and a place name. It also refers to a unit of mass used to express atomic and molecular weights, and to various geographic locations named Dalton. The most notable figure associated with the name is John Dalton, a British chemist and physicist whose work helped establish modern atomic theory.

John Dalton (1766–1844) advanced the idea that matter is composed of indivisible atoms and that elements consist of atoms with characteristic weights. He formulated the law of partial pressures, describing how the total pressure of a gas mixture equals the sum of the pressures of its components. He also studied human color vision, describing color blindness, an observation sometimes called Daltonism. His ideas laid the groundwork for modern chemistry and our understanding of gases and atomic structure.

The dalton, symbol Da (also called the unified atomic mass unit, u), is a unit of mass used to express atomic and molecular weights. One dalton is defined as one twelfth of the mass of a carbon-12 atom, approximately 1.66053906660 × 10^-27 kilograms. It is widely used in chemistry, biochemistry, and molecular biology to describe the masses of atoms and molecules.

Places named Dalton include Dalton, Georgia, the county seat of Whitfield County, and Dalton, Massachusetts. The name also appears in other locality names and administrative districts in various regions. The term’s usage spans people, science, and geography, reflecting its prominent historical and contemporary associations.