It is D,Copernicus.when he first proposed the idea everyone thought he was nuts and that it was not plausible.even though his theory wasn't so accurate it still helped further scientific research.HE was born February 19,1473 and he published a book about his theory.
Answer:
Electric Heater
Explanation
because it uses electrical energy and turns it into heat energy to heat the water.
Answer:
Potential energy is stored energy and the energy of position––gravitational energy. There are several forms of potential energy. Electrical Energy is the movement of electrical charges. Everything is made of tiny particles called atoms.
I would go with A. An Observation. Because he's looking at visual differences, for example: "based on smell, color change, and release of bubbles.