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Democritus Theory
Greek philospher Democritus (with his teacher) composed the theory that all matter was composed of indivisible elements -
John Dalton and Atoms
John Dalton develops a theory stating that all matter is composed of atoms of different weights. He had also propsed that atoms are spherical and in motion -
Cathode Ray Tubes Created
Sir William Crookes constructed a primitive cathode ray tube -
Xrays Developed
Wilhelm Rontgen discovered that certain chemicals glowed when exposed to cathode rays. -
Radiation, energy, and the atom
Pierre and Marie Curie theorized that radioactive particles cause atoms to break down, then releasing radiation that takes the form of energy and subatomic particles. -
Electrons Discovered
Electrons get discovered, using properties of cathode rays -
Einstein and the nature of light
Einstein creates theories on relativity and hypothosizes about the particle nature of light. -
Period: to
Charge of an electron measured
Robert Millikan measured the charge of a single electron, known as the elementary charge. -
Period: to
Structure of Atom Developed
Ernest Rutherford known as the father of nuclear physics, developed the theory for the structure of the atom. -
Bohr improves the atomic model
Neils Bohr developed the Bohr atomic model, with electrons travelling in orbits around the nucleus, and chemical properties being determined by how many electrons are in the outer orbits. -
Math describes electron changes
Erwin Shrodinger described how electrons move in wave form -
The neutron is discovered
James Chadwick discovers the neutron component of the atomic nucleus, explaining the nuclear fission of uranium 235.