Which of the following is an essential point of Bohr's theory regarding the structure of the hydrogen atom?

• A. The energy of an electron depends only on its speed, not its orbit.
• B. Electrons can occupy any energy level continuously between the nucleus and infinity.
• C. Electrons move in fixed circular orbits around the nucleus without radiating energy.
• D. Electrons emit energy continuously as they revolve around the nucleus.

Answer: (C)

Verified step by step guidance

1. Understand that Bohr's model of the hydrogen atom was developed to explain the stability of atoms and the discrete spectral lines observed experimentally.
2. Recall that Bohr proposed electrons move in specific, fixed circular orbits (or energy levels) around the nucleus, and these orbits correspond to quantized energy states.
3. Recognize that according to Bohr, electrons do not emit energy while they remain in these fixed orbits, which prevents the electron from spiraling into the nucleus.
4. Note that energy is only emitted or absorbed when an electron jumps from one allowed orbit to another, resulting in discrete spectral lines.
5. Therefore, the essential point of Bohr's theory is that electrons move in fixed circular orbits around the nucleus without radiating energy.