Answer: twice its value, negative.
- A twice its value, negative
- B half of its value
- C equal to its value
- D one third of its value
Correct answer: A. twice its value, negative
Explanation: PE = 2 × E<sub>total</sub> (both negative), while KE = −E<sub>total</sub>.

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.