How to be a model?

How does the quantum mechanical model of the atom correlate with the traditional Bohr model?

• How does the quantum mechanical model of the atom correlate with the traditional Bohr model? A) Both place the nucleus at the center of the atom. B) The direction in which the electron orbits in the Bohr model is the same as in the quantum mechanical model. C) The quantum mechanical electron probability cloud is completely contained within the radius of the traditional Bohr model. D) The location of highest probability for the electron is at the traditional orbital radius.

• Answer:

  A) Other than that, they are totally different. B) the QM electrons don't have direction as they come and go in space time. C) the QM clouds extend well beyond the Bohr orbits. In fact there is a rare event probability that an electron can occur on the rim of the known universe. I said it was rare. D) in the Bohr model, there are no orbitals. There are orbits. Orbitals are strictly QM and they each have no more than two electrons. So the volume of highest probability cannot correspond to an orbit. Orbitals and orbits are not even the same shape.