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 :

The absolute value of the electron gain enthalpy of halogens satisfies :

The characteristics of elements X, Y and Z with atomic numbers, respectively, 33, 53 and 83 are :

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