How would you account for the following:
(i) is an endothermic compound while is an exothermic one.
(ii) is a linear molecule without a bend.
(iii) The electron gain enthalpy with negative sign for fluorine is less than that for chlorine, still fluorine is a stronger oxidising agent than chlorine.
(i) F is more electronegative than Cl.
The difference in the electronegativity between N and F is much more than the difference between electronegativity of N and Cl. So there is need of much more energy to break the N-F bond.
(ii) In there are 2 bond pairs and 3 lone pairs and thus show hybridization. It has linear geometry.
(iii) Because of small size of flourine atom and strong electron-electron repulsions in its compact 2p orbitals.