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322
Aristotle
Disagreed with Democritus theory, and said that everything is made out of elements, and his theory was beilived for over 2,000 years -
370
democritus
Democritus, a great greek philosopher, theorized that everything is made out of atoms. -
John Dalton
Stated that 1.All matter is made of atoms. . 2) All atoms of a given element are identical in mass and properties 3) Compounds are formed by a combination of two or more different kinds of atoms. 4) A chemical reaction is a rearrangement of atoms. 5) Atoms cannot be created, divided into smaller particles, nor destroyed in the chemical proces -
Crooke
He experimented and devoluped the crooks tube experement. -
Demtri Mendeleev
Made a more reliable and factual periodic table, which is still being used today. -
John Newlands
Made the first periodic table, with only 8 elements that he said had exactly the same chemical properties. -
JJ thomson
Discoverd the electron. -
Rutherford
After experimenting with gold he discoverd that atoms have a nucleus -
Neils Bohr
came up with the atomic strucure and introduced a theory that electrons travel around a orbit. -
James chadwick
Found neutrons are are lacking in electrical charges.