Which of the following best describes how Bohr's model of the atom differs from Thomson's model?

• A. Bohr's model proposes that electrons are randomly distributed throughout the atom, similar to Thomson's model.
• B. Bohr's model does not include a nucleus, while Thomson's model does.
• C. Bohr's model places electrons in fixed energy levels around the nucleus, while Thomson's model describes electrons embedded in a positively charged 'plum pudding.'
• D. Bohr's model suggests that atoms are indivisible, whereas Thomson's model allows for atomic division.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand Thomson's model of the atom, often called the 'plum pudding' model, which describes the atom as a positively charged sphere with electrons embedded randomly within it, without a nucleus.
2. Step 2: Recognize that Bohr's model introduced the concept of a nucleus at the center of the atom, with electrons orbiting the nucleus in fixed, quantized energy levels or shells.
3. Step 3: Compare the two models by focusing on the arrangement and behavior of electrons: Thomson's model has electrons scattered randomly inside a positive sphere, while Bohr's model places electrons in specific orbits with defined energies.
4. Step 4: Note that Bohr's model explains atomic emission spectra by quantized electron transitions between energy levels, a feature absent in Thomson's model.
5. Step 5: Conclude that the key difference is Bohr's introduction of fixed electron energy levels around a nucleus, contrasting with Thomson's model of electrons embedded in a diffuse positive charge.