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Democritus
Knowing that everything is made up of atoms, Democritus was the first person to create an atomic model. His model was just a solid ball. (At this time Democritus didnt know anything about orbiting electrons or what atoms are mae up of) Democritus could not support his theory with experiments or the scientific theory. -
Jhon Dalton
Jhon Dalton's Model was also a tiny sphere of atom matter, but Jhon Dalton had evidence from scientific experiments to prove his model of the atom. In his model atoms were tiny, indestructable spheres with no internal structure. -
Thomson
Thomson discovered that atoms had a negative charge. (Electrons) He came apon this in a series of experiments.
(high-vacuum cathode-ray tube) -
Cathode Ray
Cathode rays are streams of electrons observed in vacuum tube. An evacuated glass tube has two electrodes and a voltage(really hig amounts of electricity) is applied, the glass opposite of the negative electrode is going to glow, because of the electrons forced from and travelling side to side to the cathode the electrode connected to the negative terminal of the voltage. Using this experiment chemists were able to study the nature of electric dicharge in atoms. (electric = electrons) -
Hantaro Nagaoka
Hantaro Nagaoka made a planetary model of the atom, his model was followed by saturns rings and its stirdyness. -
Rutherford
Rutherford discovered that an atom has a positivley charged ball in the middle of it called the nucleus. Electrons orbit aroumd the nucleus with their negative charge -
Rutherford's Gold-Foil Experiment
Rutherford thought that if Thomson's model was correct, then the mass of the atom was spread out throughout the atom. He decided to test this with a thin film of gold atoms. He hypothesized that the atoms would go thru and as expected, most alpha particles went right through the gold foil but something happened that he didnt hypothisize, a few alpha particles rebounded almost directly backwards. -
Henry Mosely
Henry Mosely proved the first experimental evidence of Niels Bohr's theory.Wich advanced the laws of atomic physics -
Bohr
Bohr's Atomic model is one very similar to Rutherfords Model but Bohr discovered that electrons have orbirls. Electrons orbit in a circle around the nucleus. -
The First Atomic Bomb dropped
This bomb was dropped in world war 2. America used Cockroft and Walton's idea, and split the atom to create a nucleur bomb. -
Electron Cloud
It is later dicovered that electrons are orbiting in different paths and so quickly that they create a cloud around the nuecleus. Wich is why atoms are tricky their not a gas o a solid but in the middle. We still have alot to learn from atoms.
