-
460
Democritus' Theory on Atoms
Democritus with his teacher Leucippus fist discovered the concept of the atom (which he called the atoma meaning uncuttable). His theory was if you kept cutting an object such as bread you would eventually reach a point when you cannot cut. Hence the theory of the atom was born. -
Period: 460 to
The Timeline of the Atom
The Timeline of the Atom began in 460BC -
John Dalton's Theory on Matter
Some time in 1808 John Dalton an English pharmicist was about to conclude that all matter was made up of miniscule spheres called atoms. They were able to bounce around with fill elasticity. -
Joseph John Thompson Discovers the Electron
He found that atoms could sometiems eject a smaller negative particle which he called an atom -
Joseph John Thompsons Builds the Plum Pudding Model
Thompson creates a theory that the atom was made up of electrons scattered throughout the atom unevenly with an elastic sphere surrounded by a group of positive charges to balance the atom's charge -
Ernest Rutherford and The Gold Foil Experiment
Rutherford from his gold foil experiment concluded that the atom had a central part called the nucleus. He found this by firing helium particles at gold foil. Every 8000 times or so the helium particles would bounce off hitting the nucleus. -
Niels Bohr Proposes that Electrons Where in Orbit
Niels Bohr refined Rutherfords idea by adding that the elctrons circulated around the nucleus much like planets circulating a planet. He also constructed a model for drawing atoms that is inaccurate but still in use today -
James Chadwick Discovers Neutrons
James Chadwick concluded that neutrons were in the nucleus alongside Rutherford.
