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300
Aristotle (BC)
what he discovered about the atom:
he thought that all materials on earth were not made of atoms, but of the four elements- Earth, fire, water, and air.
His method: atomic models and scientific faults
http://www.iep.utm.edu/aris-log/ -
450
Democritus BC
What he discovered about the atom:
They were the smallest part of matter, could not be broken down further.
All matter consists of invisible particles called atoms
Atoms are indestructible
Atoms are solid but invisible
Atoms are homogenous
Atoms differ in size, shape, mass, position, and arrangement
His method: the microscope method. He would put the material into a slide and it was viewded ten times larger than what it was supposed to be. http://www.nobeliefs.com/atom.htm -
Dalton
Http://www.iun.edu/~cpanhd/C101webnotes/composition/dalton.html
all atoms of a given element are identical in mass and properties
compunds are formed by a combination of two or more different kinds of atoms
all chemical reactiosn is a rearragement of atoms
described the atom as a fundemental chemical object
METHOD : microscope method
put the material into a slide and viewd ten times larger than what it was supposed to be
theory still remains vaild -
Thompson
he discovered electrons in atoms.
method: experimental
famous model:Raisin in the pudding
http://www.nobeliefs.com/atom.htm -
Thomson
he discovered electrons in an atom
methods he used: experimental
Famous name: plum pudding -
Bohr
discovered: electrons don't spiral into the nucleus and came up with rules for what actually does happen. rule 1: Electrons can orbit only at certain allowed distances from the nucleus. rule 2:
Atoms radiate energy when an electron jumps from a higher-energy orbit to a lower-energy orbit. Also, an atom absorbs energy when an electron gets boosted from a low-energy orbit to a high-energy orbit.
method: foil experiment -
Rutherford
Rutherford identified the particles of the nucleus as discrete positive charges of matter. Rutherford knocked hydrogen nuclei out of atoms of six elements: boron, fluorine, sodium, aluminum, phosphorus, an nitrogen. He named them protons, from the Greek for 'first', for they consisted of the first identified building blocks of the nuclei of all elements. He found the protons mass at 1,836 times as great as the mass of the electron.
method: experimental
name: plum pudding
http://www.nobeliefs.com -
Heisenberg and Schrodinger
