atomic theory timeline

Democritus Democritus was one of the first Greek scientists to theorize that matter was made of small indivisible particles.

John Dalton John Dalton was the first scientist the proposed the atom with ways the atom worked

Micheal Faraday Micheal Faraday theorized that the atom contained an electrical component that also was responsible for the joining of compounds

Marie and Pierre Curie Marie and Pierre Curie had discovered radiation by placing uranium salt on a photographic plate wrapped in black paper

J. J. Thomson J. J. Thomson discovered that the atom contained a positive and negative charge by experimenting with a Crookes tube

Ernest Rutherford Ernest Rutherford found out by aiming alpha particles at a sheet of gold foil that the atom was composed of a small, dense, positively charged nucleus surrounded by a cloud of negatively charged electrons

Erwin Schrodinger Erwin Schrodinger had used mathematical equations to find the probability of an electron being in any one place around the nucleus and had made an electron density map

Neils Bohr Neils Bohr had proposed that the electrons have a concentric circular orbit around the nucleus

James Chadwick James Chadwick had by bombarding beryllium with alpha particles that a unknown radiation was being emitted and that it was coming from a neutrally charged particle which was named the neutron

Robert Millikan Robert Millikan discovered the charge of an electron by dropping oil between electrodes

Joseph Luis Proust Joseph Luis Proust proposed that all compounds were the same proportions of mass as the combined elements despite how they were made

Antoine Lavoisier Antoine Lavoisier had discovered that mass was conserved in a chemical reaction and that the total mass of the product was the always the same as the total mass of the starting materials