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460
Democritus 460bc-370bc
The "creator" of the atom -
John Dalton 1766-1844
Aatoms of one element can't convert into another elrment. He also showed that molecules are made up of atoms in fixed proportions. -
Goldstein 1850-1930
He found that atoms contain positivley charged particals called protons and scenes atom contain negatively charged particals they must contain the positive particals to be electrically neutral. -
Robert Millikan 1868-1953
Determined the unit charge of the electron in 1909 with his Oil Drop Project. -
Ernest Rutherford 1871-1937
Described that the atom has a tiny dense core, which he called the Neucleus. Density meaning the neucleus has nearly all the mass. Around the neucleus is light negtive particales called electrons. These electons circulate around the core, like planets revolve around the sun. -
Neils Bohr 1885-1962
Stated that electons are in stable levels around the nucleus. -
Erwin Schrodiger
Described the montion of electrons. His work lead to the electron cloud modle.The electron cloud is a probable location of where electrons can be found. He suggested that electrons behave in a wave-like manner rather than just as particales and that their exact location within an orbit could not be precisely calculated. -
J.J. Thomson 1856-1940
Discovered that an atom was made up of positives and negatives. He discovered the electron. -
James Chadwick 1891-1947
Discovered the neutron in 1932 which led directly to the discovery of the atomic bomb.
