What is the relationship between the first ionisation enthalpy and reducing power and basic nature of element?

Arrange the following in order of increasing first ionisation enthalpy:
Mg, Al, Si, Na.

Name the element in the periodic table with maximum I.E., value.

Out of Na and Na⁺, which has higher ionisation enthalpy?

46.

Which one of the following statements is incorrect in relation to ionization enthalpy?
(a) Ionization enthalpy increases for each successive electron.
(b) The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration.
(c) End of valence electrons is marked by a big jump in ionization enthalpy.
(d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.

Considering the elements B, Al, Mg, and K, the correct order of their metallic character is:
(a) B > Al > Mg > K                         (b) Al> Mg> B > k
(c) Mg > Al > K > B                         (d) K > Mg > Al > B 

Considering the elements B, C, N, F and Si, the correct order of their non-metallic character is:
(a) B> C > Si > N > F                  (b)  Si > C > B > N > F
(c)  F > N > C > B > Si                (d) F > N > C > Si > B

Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidizing property is:
(a) F > Cl > O > N                               (b) F > O > Cl > N
(c) Cl> F >O > N                                  (d) O > F > N > Cl

The second ionisation enthalpy of an atom is greater than its first ionisation enthalpy because __________.