Democritus was an Ancient Greek pre-Socratic philosopher primarily remembered today for his formulation of an atomic theory of the universe.
John Dalton was an English chemist, physicist, and meteorologist. He is best known for proposing the modern atomic theory and for his research into color blindness, sometimes referred to as Daltonism in his honor.
Thomson OM PRS was an English physicist and Nobel Laureate in Physics, discovery of the first subatomic particle.
Electron Cloud Model
Ernest Rutherford, 1st Baron Rutherford of Nelson, OM, FRS was a New Zealand-born British physicist who came to be known as the father of nuclear physics.
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922.
Electron Cloud Model is an informal term in physics. It is used to describe where electrons are when they go around the nucleus of an atom. The electron cloud model is different from the older Bohr atomic model by Niels Bohr.