Step-by-step explanation:
Conductivity is defined as the ability of a substance to freely flow the electrons from one point to another.
When electrons are able to flow freely through a material then it is considered a good conductor. But if electrons are not able to move freely then it is known as a bad conductor.
Whereas reactivity of a substance depends on the number of valence electrons present in it.
For example, alkali metals are highly reactive in nature due to the presence of one valence electron.
Thus, we can conclude that both conductivity and reactivity have electrons in common.