* John Dalton (1766-1844) is considered the "father of modern atomic theory". He used experimental evidence and scientific tools to develop his atomic theory, which included the following key points:

* All matter is made up of tiny particles called atoms.

* Atoms of a given element are identical in mass and properties.

* Atoms cannot be created or destroyed in chemical reactions, but they can be rearranged.

* Compounds are formed when atoms of different elements combine in specific ratios.

* Aristotle (384-322 BC) was a philosopher who believed that matter was continuous and could be infinitely divided. He didn't use experiments to study matter.

* Democritus (460-370 BC) was a philosopher who proposed the idea of atoms. However, he didn't perform any experiments to support his ideas. His ideas were based on philosophical reasoning, not scientific evidence.

In summary: While Democritus had the initial concept of atoms, Dalton is credited with using scientific methods and experiments to develop a more comprehensive and accurate atomic theory.