Final answer:
The statement that is not true of Bohr's model is that 'Electrons can exist in any energy level.' Bohr's model dictates that electrons must occupy specific, quantized energy levels, and this is fundamental to its explanation of atomic spectra, especially in hydrogen. Option 4 is correct.
Step-by-step explanation:
The question asks which statement is not true of Bohr's model of the atom. According to Bohr's model, electrons move in fixed orbits around the nucleus (energy levels) and can only exist in certain energy levels. Furthermore, electrons emit energy when they transition from a higher to a lower energy level.
Therefore, the statement that is not true of Bohr's model is: 4) Electrons can exist in any energy level. This is incorrect because Bohr's model suggests that electrons must occupy specific, quantized energy levels.
This is analogous to a person only being able to stand on the rungs of a ladder, not in between. Bohr's model specifies that electrons in the electron cloud of an atom must be in one of those quantized energy levels.
Bohr's model was particularly successful in describing the atomic spectra of hydrogen, explaining the discrete lines seen in its emission spectrum as a result of electrons jumping between fixed energy levels.
However, one limitation of the model is that it did not explain why only certain orbits or energy levels are allowed, which was later addressed by quantum mechanics.