Choose the number of CORRECT statement(s) from the following 
(a) 1st ionisation potential of "B' is higher than that of Be'. 
(b) Electron affinity of O' is higher than that of 'S'. 

$\text{ (c) }\left[\mathrm{Ar}\right]4s^{2}3d^3\text{ is the electronic configuration of }{\mathrm{Mn}}^{2+}\text{. }$

(d) 2nd ionisation potential of Na > Ist ionisation potential of Na. 
(e) Ist ionisation potential of N > 2nd ionisation potential of N. 
(f) Electronegativity of Cl > Electronegativity of F.

$\text{ (g) }\mathrm{C}⟶{\mathrm{C}}^{2+}\text{ change is called }2\text{ nd ionisation potential of carbon. }$

$\text{ (h) Energy is required to convert }\mathrm{He}⟶{\mathrm{He}}^{-}$

$\text{ (i) Conversion of }\mathrm{O}⟶{\mathrm{O}}^{2-}\text{ is exothermic. }$