John Dalton

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. Ideas about atoms were based on philosophy before John Dalton came up with his theory.

His theory stated that:
Atoms cannot be divided
Everything is made of atoms
Atoms can not be made or destroyed, just as energy
Atoms are tiny particles
Atoms can only be joined in special ratios
Atoms of the same element are the same, because they have the same atomic mass
Chemical reactions are made when atoms are moved around, put with other atoms or taken away from a group of other atoms

 Further readings 
 Claus Bernet: John Dalton (1766-1844), in: Biographisches-bibliographisches Kirchenlexikon, 31, 2010, 309-332.

 References 

 Other websites 
 John Dalton -Citizendium 

Category:1766 births
Category:1844 deaths
Category:English chemists
Category:English physicists
Category:British nuclear physicists