History of the atom Flashcards
who invented the plum pudding model?
jj.thompson in 1904
what was the plum pudding model?
a sphere of positive charge, embedded with negatively charged particles called electrons
who invented the nuclear model of the atom?
Rutherford by the scattering experiment
what was the nuclear model of the atom?
proved the existence of a positively charged nucleus and that the mass of the atom was concentrated inside the nucleus and most of the atom is empty space.
what was the scattering experiment?
Rutherford fired alpha particles at thin gold foil, most particles went through, some were slightly deflected and some repelled back to where they were fired from proving the existence of a positively charged nucleus in the middle of the atom and most of the atom is empty space.
what did Niels Bohr suggest?
Electrons orbit the nucleus at certain distances, called energy levels, now called electron shells.
who discovered the existence of the neutron?
James Chadwick
what is an isotope?
An atom with the same number of protons but different number of neutrons