what was the idea of the atom before dalton
1 All atoms of a given element are identical; atoms of different elements have different properties. 2  Dalton's theory suggested that every single atom of an element such as oxygen is identical to every other oxygen atom; furthermore, atoms of different elements, such as oxygen and mercury, are different from each other.ecause of Aristotle's great influence, Democritus's theory would have to wait almost 2,000 years before being rediscovered. In the seventeenth and eighteenth centuries CE, several key events helped revive the theory that matter was made of small, indivisible particles.