Predict from each set, the atom/ion which has the greatest `IE_(1)` with explanation:
a. `Cl` or `F` , b. `S` or `Cl`
c. `Ar` or `K` , d. `Xe` or `Kr`
e. `O` or `N` , f. `Na^(o+)` or `Na`
g. `Be^(o+)` or `Mg^(2+)` , h. `I^(ɵ)` or `I`
i. `B` or `C` , j. `Ne` or `F`
k. `N, O,F` l. `P,Ar,Mg`
m. `B,Al,Ga`

Explanation

a. `F` [Small size, more `Z_(eff)`, less shielding effect, high `IE_(1)` of `F`]
b. `Cl[Cl]` has high `IE_(1)` due to small size, high nuclear charge]
c. `Ar` [ `Ar` has high `IE`, due to stable configuration `K` has low `IE` than `Ar`, becuae `K` has one more electron than `Ar`, and hence can easily lose this electron to acquire stable `Ar` configuration]
d. `Kr` [`Kr` has high `IE_(1)`, because of smaller size than that of `Xe`, and weaker shielding effect in `Kr`]
e. `N[ N` has high `IE_(1)` because an electron has to be lost from a stable half-filled electronic configuration. In case of `O`, loss of electron gives `O^(o+)` which has stable exactly half-filled electronic configuration]
g. `Mg^(2+)` [In case of `Mg^(2+)`, the electron has to be lost from the stable gas inert gas configuration, but in case of `Na`, loss of electron gives a stableinert gas configuration. Hence `IE` of `Mg^(2+) gt Be^(o+)`]
h. `I^(ɵ) [IE` of `I^(ɵ) gt I`, becasue in case of `I^(ɵ)` an electron has to be lost from inert gas configuration]
i. `C[IE` of `C gt B`, because of higher muclear charge in `C`]
j. `Ne [IE` of `Ne gt F`, because of stable inert gas configuration in `Ne`]
k. `F` [All belong to 2nd period. `IE` of `F gt N gt O` since `F` has the highest charge, and the smallest size among them]
l. `Ar`[All belong to 3rd period, `IE` of `Ar gt P gt Mg. Ar` has stable inert gas configuration]
m. `B`[All belong to group 12. `IE_(1)` of `B gt Ga gt Al (800 gt 578 gt 577)`, because of the smallest size and weaker shielding effect of `B`]