For question 15, the correct response would be A. Small atomic radii and high ionization energies, the amount of required energy needed to detach and or remove a single valence electron from the corresponding electron shell the electron that one wishes to remove is from. For Q 16, it would be A. They are extremely reactive, as they can easily remove and or detach a valence electron so that it can be used for transferring to a nonmetal atom, and allow for the formation of an ionic bond. It does not require as much energy to remove a outermost electron and react to form a bond than metal atoms with higher ionization energies.