Answer:
You know that a chemical reaction has taken place because there is a material a color change.
Explanation:
It is unique for many many ways:
1.)<span>Unlike the other </span>planets<span> of the solar system, </span>Uranus<span> is tilted so far that it essentially orbits the sun on its side, with the axis of its spin nearly pointing at the star. This </span>unusual <span>orientation might be due to a collision with a </span>planet<span>-size body, or several small bodies, soon after it was formed</span>
I believe it should be when he arranged the elements by their atomic mass.
Answer:
There is no answer choices