Answer: Position and momentum cannot both be known precisely.
- A Energy and time cannot both be known to arbitrary precision simultaneously
- B Position and momentum cannot both be known precisely
- C Velocity of a particle can never be measured by any method
- D The mass and charge of a particle are inherently uncertain quantities
Correct answer: B. Position and momentum cannot both be known precisely
Explanation: delta_x x delta_p >= h/(4pi). Position and momentum cannot simultaneously be known with arbitrary precision.
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.