N3−>O2−<F−<Na+(Nuclear charge)
LiK>Cs(IE)1
O2−>Ne>Mg2+>Al3+(Size)
Li>Be>B>C(Electron gain enthalpy)
In any group zero group elements i.e inert gases have greatest size as their van der Waal's radius is measured instead of covalent, so O2−>Ne>Mg2+>Al3+ size order is incorrect.