Development Of The Model Of The Atom Flashcards
What did John dalton do ?
Around the start of the 19th century he described atoms as solid spheres for the first time
What did JJ Thomson do ?
1897, he does the plum pudding model: the atom is a ball of positive charge with negative electrons embedded in it. He named it the plum pudding model.
What did Rutherford do ?
1909, alpha scattering experiment: he fired alpha particles at gold foil, most of the alpha particles went straight through showing it was mainly empty space. mass concentrated at the centre; the nucleus is charged. Most of the mass is in the nucleus. most atoms are empty space and the electron orbits the nucleus this was the first nuclear model.
What did Niels Bohr do?
Around 1911, electrons are in shells orbiting the nucleus at a specific distance
What did James Chadwick do ?
Around 1940 he discovered that there are neutrons in the nucleus.