John+Dalton+-+Erwin+and+Elliott

John Dalton was a scientist that revived and greatly expanded on the atomic theory originally proposed by the early Greek scientists. Some of his theories were: All matter is made up of elements and compounds. Elements and compounds are made up of tiny particles called atoms that are held together by invisible forces of attraction. Atoms cannot be created, divided into smaller particles, nor destroyed in the chemical process; a chemical reaction simply changes the way atoms are grouped together The atoms of a given element are different from those of any other element; the atoms of different elements can be distinguished from one another by their respective relative atomic weights. The atoms of the same element are identical and have the same mass.

Dalton had an atomic theory that states the idea that atoms have the same masses. He said that when atoms are joined, separated or rearranged chemical reactions occur. But, when a chemical reaction occurs atoms aren't changed into other atoms. He also proposes that atoms can combine with other atoms of different elements. But they always combine in whole number ratios. Salt for example (sodium chloride) has a 1:1 ratio as it is made up from one sodium atom and one chlorine atom. Water however has a ratio of 1:2 it is made up of two hydrogen atoms and one oxygen atom.