In which of the following, elements are arranged in the correct order of their electron gain enthalpies?

In second period of the long form of the periodic table an element $$X$$ has second lowest first ionisation enthalpy and element $$Y$$ has second highest first ionisation enthalpy values. What are $$X$$ and $$Y$$ ?

The set of molecules in which the central atom is not obeying the octet rule is

The formal charges of atoms (1), (2) and (3) in the ion is