Which of the following properties does not depend on periodicity?

Given below are two statements:
Statement $I$: The second ionisation enthalpy of $Na$ is larger than the corresponding ionisation enthalpy of $Mg$.
Statement $II$: The ionic radius of $O^{2-}$ is larger than that of $F^{-}$.
In the light of the above statements,choose the correct answer from the options given below.

Diagonal relationship is shown by

Elements having atomic numbers $33, 47, 53, 59, 68, 74, 82$ are present in which blocks of the periodic table?

Which one of the following sets of ions represents the collection of isoelectronic species?

Among the elements $B$,$Al$,$C$,and $Si$,
$(a)$ which element has the highest first ionisation enthalpy?
$(b)$ which element has the most metallic character? Justify your answer in each case.