History Of The Atom Flashcards
Who described the atoms as a solid sphere and when ?
John Dalton - 19th century
Who developed the Plum Pudding Model and what was it ?
J J Thompson in 1897 - measurements of the charge and mass showed the atom must contain even smaller negatively charge particles ‘electrons’
Who disproved the Plum Pudding Model and when and with what ?
Ernest Rutherford - 1909 with the alpha particle scattering experiments
Fired positively charged alpha particles at a thin sheet of gold but some passed straight through and others deflected
What did Ernest Rutherford come up with ?
Nuclear Model with a positively charged nucleus at the centre with empty space
Who disproved Ernest Rutherford’s model
Niels Bohr
What did Niels Bohr come up with ?
Electrons were in fixed shells and orbited with a fixed distance from the nucleus
What did Ernest Rutherford do to further improve the atoms existence ?
More experiments showing the nucleus can be divided.
What happened after 20 years of the discovery of the nucleus ?
James Chadwick provides evidence of neutral particles named neutrons it is known as the nuclear model
