Identify the elements X and Y using the ionisation energy values given below :

	Ionization energy (kJ/mol)
	1$${st}$$	2$${nd}$$
X	495	4563
Y	731	1450

In the above reaction, the reagent ''A'' is :

Arrange the following metal complex/compounds in the increasing order of spin only magnetic moment. Presume all the three, high spin system.

(Atomic numbers Ce = 58, Gd = 64 and Eu = 63)

(a) (NH₄)₂[Ce(NO₃)₆]

(b) Gd(NO₃)₃ and

(c) Eu(NO₃)₃

Identify the reagent(s) 'A' and condition(s) for the reaction