-
400 BCE
Democritus
An Ancient Greek pre-Socratic philosopher who is remembered for his atomic theory of the universe. His atomic theory of the universe mainly stated that all matter consists of invisible particles called atoms, atoms are indestructible, and that they differ in size, shape, mass position, and arrangement. -
John Dalton
An English chemist and physicist who is best known for proposing the modern atomic theory. He states that elements exist in packs of matter and he also created the first chart for atomic ratios and weight. -
Eugene Goldstein
A German physicist who is most known for the discovery of anode rays. He also found that there is a positive charge in matter using cathode rays. -
JJ Thompson
An English physicist who is best known for the discovery and recognization of the electron. He discovered electrons by noticing that cathode rays are 100x lighter than the smallest known particle, and then proposing that the rays were packed with electrons. -
Ernest Rutherford
A British physicist who came to be known as the "Father of Nuclear Physics". He discovered that atoms were made up of a charged nucleus orbited by electrons. -
Niels Bohr
A Danish physicist who made beiginning discoveries about atomic structures. He made a model showing that electrons were small negatively charged particles that orbit the nucleus, that protons are in the nucleus, and that some elements absorb or reflect light.
