P2 - Atomic Structure Flashcards
What did J J Thomson discover?
That electrons could be removed from atoms.
What did J J Thomson suggest?
That atoms where spheres of positive charge with negative electrons stuck in them like a plum pudding.
What did Rutherford and Marsden do in 1909?
Fired beams of alpha particles at thin gold foil.
What did Rutherford and Marsden expect to see during the alpha particle experiment?
The expected that the positive charged alpha particles would be slightly deflected by the electrons.
What actually happened during the alpha particle experiment?
Most alpha particles went straight through but a few came straight back at them.
What did Rutherford and Marsden conclude from the alpha particle experiment? [3].
1) most of the mass of the atom was in the centre in a nucleus.
2) the nucleus has a positive charge, because it repelled the positive alpha particles.
3) most of the atom is empty space.
What does the nucleus give the atom?
Mass.
What do the electrons give the atom?
Size.
What are the relative masses of the particles in an atom? [3].
Proton: 1.
Neutron: 1.
Electron: 1/2000.
What are the relative charges of the particles in an atom?
Proton: +1.
Neutron: 0.
Electron: -1.
What was John Daltons atomic structure theory?
That each element was made up of different types of atom.
