Answer: Angular momentum = nh/2π.
- A Zero angular momentum
- B Angular momentum = nh/2π
- C Angular momentum = h/2π only
- D Any value of angular momentum
Correct answer: B. Angular momentum = nh/2π
Explanation: Bohr postulate: angular momentum L = nh/(2π) = n × hbar. Quantized in integer multiples of hbar.

The Geiger–Marsden alpha-scattering result: a few alpha particles bounce back at large angles, which rules out Thomson’s diffuse model and demands a tiny, massive, positively charged nucleus. Image: Kurzon, CC BY 3.0, via Wikimedia Commons.
Concept context
Thomson's plum-pudding model, Rutherford's nuclear model from alpha-scattering, Bohr's postulates and hydrogen spectrum, spectral series (Lyman to Pfund), Rydberg formula, and limitations of each model.