Consider the following ionization enthalpies of two elements 'A' and 'B' .

Element	Ionization enthalpy (kJ/mol)
	1st	2nd	3rd
A	899	1757	14847
B	737	1450	7731

Which of the following statements is correct ?

If the shortest wavelength in Lyman series of hydrogen atom is A, then the longest wavelength in Paschen series of He⁺ is :

The enthalpy change on freezing of 1 mol of water at 5^oC to ice at −5^oC is :

(Given $$\Delta $$_fusH = 6 kJ mol^$$-$$1 at 0^oC,
C_p(H₂O, $$\ell $$ = 75.3J mol^$$-$$1 K^$$-$$1)
C_p(H₂O s) =36.8 J mol^$$-$$1 K^$$-$$1)

A metal ‘M’ reacts with nitrogen gas to afford ‘M₃N’. ‘M₃N’ on heating at high temperature gives back ‘M’ and on reaction with water produces a gas ‘B’. Gas ‘B’ reacts with aqueous solution of CuSO₄ to form a deep blue compound. ‘M’ and ‘B’ respectively are :