If an atom gains electrons, it develops a negative charge equal to the number of electrons gained.
So the net charge on the copper atom which gained 2 electrons will be -2.
Kinetic Energy would have to be the answer. Pretty sure.
Below are the 5 main indicators of chemical change.
Chemical change indicators:<span>
Color change
</span>Temperature change
Precipitate formation<span>
Odor
Bubble formation
I hope this helps!</span>
FALSE <span>Only electromagnetic </span>waves<span> can </span>travel through a vacuum<span>; mechanical </span>waves<span> such as sound </span>waves<span> require a particle-interaction to transport their energy. There are no particles in a </span>vacuum<span>. </span>Waves<span> are either </span>longitudinal<span> or transverse.
</span>Hoped i helped :):)