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400 BCE
Democritus
Introduced the idea of the atom as the basic building block of matter. -
410
The Battle of Cyzicus
The Battle of Cyzicus in 410 BCE. where Alcioiades and the Athenians anbushed or outmaneuvered the Poloponnesian fleet, destroying ships and killing its admiral -
treaty with France and Quasi war
On July 7, 1798, congress rescinded treaties with France and the Quasi war begins -
John Dalton
All matter was comprised of individuals and indestructible atoms with distinct masses and properties. The combination of which determines the physical nature of their constituent elements. " Modern theory of the atom.
"Marble model" -
Michael Faraday
Discovered that atoms have an electrical component. He discovered this when studying the properties an reactions of electrolysis -
JJ Thomson
Experimented with cathode ray tubes showed that al atoms contained tiny negatively charged subatomic particles or elements.
"Plum pudding model" -
Eugen Goldstein
discovered evidence for the existence of this positively charged particle -
The wounded Knee Massacre
On December 29 1890, The Wounded Knee Massacre took place in South Dakota when U.S calvary troopers fired on Lakota people who had gathered -
Robert Peary Conquest to the north pole
Robert Peary began his Conquest to the North Pole on April 6, 1909 -
Robert Millikan
Succeeded in precisely determining the magnitude of the electron change -
Ernest Rutherford
The Atom is mostly empty space, with nearly all of its mass concentrated in a tiny central nucleus
"Nuclear model" or "Jimmy Neutron model" -
Neils Bohr
A model of the atom in which the electron was able to occupy only certain orbits around the nucleus. "Solar system" model -
Ninetieth amendment
On August 18 the ninetieth amendment was passed giving women the right to vote. -
Werner Heisenberg
He contributed to atomic theory by formulating quantum mechanics in terms of matices and in discovering the uncertainty principle. -
Edwin Schrödinger
a powered model of the atom was developed in 1926.
"Electron cloud model" -
The Great Mississippi Flood
The great Mississippi flood of 1927 strikes 700,000 people in the greatest natural disaster in American history through this time -
James Chadwick
He proved the existence of neutrons-elementary particles devoid of any electrical charge. "electron cloud model with neutrons added"