A theory of chemical combination, first stated by John Dalton in 1803. It involves the following postulates:
(1) Elements consist of indivisible small particles (atoms).
(2) All atoms of the same element are identical; different elements have different types of atom.
(3) Atoms can neither be created nor destroyed.
(4) ‘Compound elements’ (i.e. compounds) are formed when atoms of different elements join in simple ratios to form ‘compound atoms’ (i.e. molecules).
Dalton also proposed symbols for atoms of different elements (later replaced by the present notation using letters).
Chemistry
A theory of chemical combination, first stated by John Dalton in 1803. It involves the following postulates:
(1) Elements consist of indivisible small particles (atoms).
(2) All atoms of the same element are identical; different elements have different types of atom.
(3) Atoms can neither be created nor destroyed.
(4) ‘Compound elements’ (i.e. compounds) are formed when atoms of different elements join in simple ratios to form ‘compound atoms’ (i.e. molecules).
Dalton also proposed symbols for atoms of different elements (later replaced by the present notation using letters).
Chemical Engineering
A theory of chemical combination first postulated in 1803 by British chemist and physicist John Dalton (1766–1844). It includes the postulates that elements are made of individual particles (atoms); that atoms of the same element are identical and that different elements have different types of atoms; that atoms can be neither created nor destroyed; and that so-called ‘compound elements’ are formed when different elements join together to form molecules. He proposed symbols for the different elements that were later replaced by the present notation for chemical elements.