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Democritus
In matter the atoms are indestructible units which means that they are stable and they do not break apart. The atoms do not change form and move around to combine different form of a molecule. He also made up a term called, Atomos. Atomos matter can be cut until it can not be cut anymore. -
Antoine Lavoisier
Introduced the metric system, Introduced the identification of hydrogen and oxygen -
Law of Conservation of Mass
Established in 1789 by a french scientist by the name of Antoine Lavioser. States that mass is neither created or destroyed. -
Dalton's Atomic Theory
He proposed the Law of Multiple Proportions. This law led directly to the proposal of hte Atomic Theory in 1803. -
John Dalton
He developed the concept of the mole and proposed a system of symbols to represent atoms of different elements. He recognized the existence of atoms of elements and that compounds formed from the union of these atoms. He therefore assumed that simplest ratios would be used in nature and came up with a formula for water. He then assigned a relative atomic weight of one to hydrogen and developed a relative atomic weight scale from percent composition data and assumed atomic ratios. -
Dmitri Mendeleev
Credited as being the creator of the first periodic table of elements. -
Cathode Ray Tube
vaccum tube containg one or maore electron guns and a florescent screen used to view images -
JJ Thomson
Credited for finding the first ecidence for isotopes of a stable element in 1913. -
Plum Pudding Atomic Model
An atom model that was proposed by JJ thompson, the physist who discovered the electron. -
Robert Millikan
Earliest succes was the accurate determination of the charge carried by an electron -
Rutherford Model
A model of the atom devised by ernist rutherford -
Henry Moseley
His law advanced atomic physics by providing the first expirimental evidencein favor of Neils theory -
Bohr Planetary
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Niels Bohr
Made contributions to the understanding of the atomic structure and quantum theory -
Gold Foil Experiment
Expiriment to prove the structure of the atom. -
Erwin Schrodinger
Developed a number of fundamental results in the field of the quantum theory, which formed the basis for mechanics. -
Quantum Mechanical Model
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Ernest Rutherford
Discovered the concept of radioactive half-life, proved that radioactivity involved the transmulation of one chemical element to another -
James Chadwick
was awarded the noble prize in physics for his discovery of the neutron -
Electron Cloud Model
An atom model where electrons are no longer depicted as particles moving around the nucleus as a fixed orbit.
