Search results
Results From The WOW.Com Content Network
This is an accepted version of this page This is the latest accepted revision, reviewed on 19 September 2024. British chemist and physicist (1766–1844) For other people named John Dalton, see John Dalton (disambiguation). John Dalton FRS Dalton by Thomas Phillips, 1835 Born (1766-09-06) 6 September 1766 Eaglesfield, Cumberland, England Died 27 July 1844 (1844-07-27) (aged 77) Manchester ...
History of atomic theory. The current theoretical model of the atom involves a dense nucleus surrounded by a probabilistic "cloud" of electrons. Atomic theory is the scientific theory that matter is composed of particles called atoms. The definition of the word "atom" has changed over the years in response to scientific discoveries.
Atomism. Atomism (from Greek ἄτομον, atomon, i.e. "uncuttable, indivisible") [1][2][3] is a natural philosophy proposing that the physical universe is composed of fundamental indivisible components known as atoms. References to the concept of atomism and its atoms appeared in both ancient Greek and ancient Indian philosophical traditions.
In 1804, Dalton explained his atomic theory to his friend and fellow chemist Thomas Thomson, who published an explanation of Dalton's theory in his book A System of Chemistry in 1807. According to Thomson, Dalton's idea first occurred to him when experimenting with "olefiant gas" ( ethylene ) and "carburetted hydrogen gas" ( methane ).
But this ancient idea was based in philosophical reasoning rather than scientific reasoning. Modern atomic theory is not based on these old concepts. [1] [2] In the early 19th century, the scientist John Dalton (1766–1844) found evidence that matter really is composed of discrete units, and so applied the word atom to those units. [3]
Dalton's 1806 list of known elements by atomic weight. In 1808–10, British natural philosopher John Dalton published a method by which to arrive at provisional atomic weights for the elements known in his day, from stoichiometric measurements and reasonable inferences. Dalton's atomic theory was adopted by many chemists during the 1810s and ...
After Dalton published his atomic theory in 1808, certain of his central ideas were soon adopted by most chemists. However, uncertainty persisted for half a century about how atomic theory was to be configured and applied to concrete situations; chemists in different countries developed several different incompatible atomistic systems.
Dalton's idea also differed from the idea of corpuscular theory of matter, which believed that all atoms were the same, and had been a supported theory since the 17th century. [19] To help support his idea, Dalton worked on defining the relative weights of atoms in chemicals in his work New System of Chemical Philosophy, published in 1808. [19]