In the simplified Bohr model of the atom, which scientist proposed that electrons occupy discrete energy shells (quantized energy levels) around the nucleus?

• A. Ernest Rutherford
• B. James Chadwick
• C. Niels Bohr
• D. J. J. Thomson

Answer: (C)

Verified step by step guidance

1. Understand the context of the Bohr model, which is an early atomic model explaining how electrons are arranged around the nucleus.
2. Recall that the Bohr model introduced the idea that electrons do not orbit the nucleus randomly but instead occupy specific, fixed energy levels or shells.
3. Identify the scientist associated with this model: Niels Bohr proposed that electrons exist in quantized energy levels, meaning electrons can only have certain allowed energies.
4. Recognize that other scientists listed, such as Ernest Rutherford, James Chadwick, and J. J. Thomson, contributed to atomic theory but did not propose the quantized energy shells concept.
5. Conclude that the correct answer is Niels Bohr, as he introduced the concept of discrete energy levels in the atom.