Answer:
A positive ions is always smaller than the corresponding atom.
A negative ion is always larger than the corresponding atom.
Explanation:
The reason for this is that, when a positive ion is formed, a full shell is usually removed with its electrons thereby reducing the size of the electron cloud and decreasing the size of the electron cloud.
A negative ion is formed by addition of more electrons to the electron cloud hence it spreads out. Interelectronic repulsion accounts for the larger size of the negative ion.
Light does not travel at a constant speed in a vacuum, compared to in air, because the light is being absorbed by atoms and molecules in the air. But light does travel at a constant speed in a vacuum.
So I agree with A
All that talk about moving forward is irrelevant (I think)
It increases as temperature rises.
