4km I believe is the answer
I think the correct answer would be C. The common characteristic that is shareed by the elements found at the center of a period would be that they are the least reactive species. Having lower value of electronegativity, there is less ionization of the atoms which would also contribute to less reactivity.
Explanation:
Electrons are closer to the nucleus are in filled orbitals and are called core electrons. More energy which in nucleus called nuclear strOng energy to remove electron thars why its also a way harder too..
Answer:
Their isn't your examples but I will give you mine
Freezing, Evaporation and so on.