<span> red litmus paper turns </span>blue <span>under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F). Neutral litmus paper is purple.</span>
A. Thermal energy good job
Answer:
He conducted an experiment using gold foil and alpha particles.
Explanation:
Ernest Rutherford in 1911 performed the gold foil experiment which provided a better outlook to the structure of the atom. In his experiment, he bombarded a thin gold foil with alpha particles. Most of the alpha particles passed through the gold foil and just a few was deflected back.
This observation led Rutherford to propose the nuclear model of the atom in which an atom has a small positively charged centre and electrons moving round it.