John Dalton (6 September 1766–27 July 1844) was a British chemist and physicist. He was born in Cumberland to a Quaker family. He is best known for his discoveries in atomic theory. He also made the first important studies of color blindness.
Dalton's Atomic Theory
Dalton's Atomic theory is a scientific theory about atoms. Dalton made the theory to explain why the elements would combine in certain ways The idea of atoms was already known at the time, but not widely accepted. Dalton's theory of atoms was based on actual observation. Before this, ideas about atoms were based more on philosophy.
His theory stated that:
- Everything is made from atoms
- Nothing can be simpler than an atom
- Atoms can not be made or destroyed
- Chemical reactions are made when atoms are moved around, put with other atoms or taken away from a group of other atoms
- Atoms of the same element are the same, because they have the same atomic mass.
- Atoms can only be joined in special ratios (see Law of definite composition
- Claus Bernet: John Dalton (1766-1844), in: Biographisches-bibliographisches Kirchenlexikon, 31, 2010, 309-332.