The first ionization energy of magnesium is smaller as compared to that of elements X and Y, but higher than that of Z. The elements X, Y and Z, respectively, are :

Match List - I with List - II :

	List - I		List - II
(a)	Mercury	(i)	Vapour phase refining
(b)	Copper	(ii)	Distillation refining
(c)	Silicon	(iii)	Electrolytic refining
(d)	Nickel	(iv)	Zone refining

Choose the most appropriate answer from the option given below :

Given below are two statements :

Statement I : Bohr's theory accounts for the stability and line spectrum of Li⁺ ion.

Statement II : Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic field.

In the light of the above statements, choose the most appropriate answer from the options given below :

The oxidation states of nitrogen in NO, NO₂, N₂O and NO$$_3^ - $$ are in the order of :