DALTON’S ATOMIC THEORY

Democritus first suggested the existence of the atom but it took almost two millennia before the atom was placed on a solid foothold as a fundamental chemical object by john Dalton (1766-1844). Although two centuries old, Dalton’s atomic theory remains valid in modern chemical thought

Dalton’s atomic theory

1.       All matter is made of atoms. Are invisible and indestructible

2.       All atoms of a given element are identical in mass and properties

3.       Compounds are formed by a combination of two or more different kinds of atom

4.       A chemical reaction is a rearrangement of atom

Modern atomic theory is, of course, a little more involved than Dalton’s theory but the essence of Dalton’s theory remains valid. Today we know that atoms can be destroyed via nuclear reactions but no by chemical reactions. Also, there are different kinds of atoms (differencing by their masses) within an element that are known as “isotopes”, but isotopes of an element have the same chemical properties.