Question

Compare the modern (electron cloud) model of the atom with Bohr’s atomic model. Which of these statements describe the two models correctly? Check all of the boxes that apply.

Bohr’s model was replaced only because of its age.

Bohr’s model electrons cannot exist between orbits, but in the electron cloud model the location of the electrons cannot be predicted.

The modern model explains all available data about atoms; Bohr’s model does not.

The modern model is more widely accepted because it was proposed by more well known scientists.

Answer 1

Check the following two statements:

- Bohr’s model electrons cannot exist between orbits, but in the electron cloud model the location of the electrons cannot be predicted. — Correct.
- Bohr’s model had fixed, quantized orbits and disallowed intermediate energies. The modern (quantum/electron‑cloud) model does not give exact electron positions; it gives probability distributions (orbitals).

- The modern model explains all available data about atoms; Bohr’s model does not. — Correct (in the intended classroom sense).
- The quantum model accounts for hydrogen and multi‑electron atoms, chemical behavior, fine structure, etc.; Bohr’s model only worked well for hydrogen and failed for many other observations.

Do not check these:

- Bohr’s model was replaced only because of its age. — Incorrect. It was replaced because experiments and theory showed it was inadequate.

- The modern model is more widely accepted because it was proposed by more well known scientists. — Incorrect. Acceptance is based on predictive power and agreement with experiment, not the fame of the proposers.