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460
Democritus
Democritus a greek philosopher also so known as the "Laughing philosopher." Said that all things originated from a vortex of tiny partices called atoms. -
Period: 460 to
Atomic Theory
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Antonie Lavoisier
Lavoisier in known as the father of modern chemistry and for naming many elements.And also establishing sulfur as an element. -
Law of Conservation of Mass
Prposed by Antoine Lavoisier which states that mass cannot be created nor destroyed. -
Daltons Atomic Theory
Said that a pure substance is pure to the last atom.Meaning that gold is gold till the last atom. -
John Dalton
Said and is still used today that atoms cannot be subdivided, created, or destroyed. -
Dmtri Mendeleev
The creator of the first periodic table of elements -
Cathode Ray Tube
Conducted by J.J Thomson showed a ray of negativley charged particles called electrons. -
J.J Thomson
Thomson identified that electrons were part of an atom. -
Plum Pudding Model
The plum pudding model showed how a negatively charged nucleus was surrounded by a positively particles. -
Gold Foil Experiment
This expirement showed that most of the atoms mass is located in the dense region known as the nucleus. -
Robert Millikan
Experimented the elementary electric charge (charge of the electron) to prove a negative charge. -
Rutherford's Model
Rutherford's model is basicly the planetary system.Revised by Niels Bohr sometimes called the Rutherford-Bohr Model. -
Ernest Rutherford
He postulated the structure of the atom.He found positively charged central reigion. -
Niels Bohr
Niels Bohr was the man that made the Bohr Planetary model. -
Henry Moseley
The first periodic table by atomic number. -
Bohr Planetary Model
It was a model of an atom much like the solar system showing the nucleus acting as the sun surrounded by electrons acting as planets held together by an electrostatic force mush like gravity. -
Erwin Schrodinger
Erwin was the first to suggest how the electrons were spaced throughout an atom. -
Quantum Mechanical Model
Made by Erwin Schrodinger correctly defines the electrons movement with the relation to the nucleus. Shows that electrons are in random motionconfined within areas. -
Electron Cloud Model
Created by Erwin Schrodinger. It is a space of an atom where electrons are likley to be found. -
James Chadwick
Chadwick discoverd a no charge particle called a neutron.Crucial for the discovery of Uranium-235 and plutonium.
