Given below are two statements: Statement I: The second ionization enthalpy of B, Al and Ga is in the order of B > Al > Ga. Statement II: The correct order in terms of first ionization enthalpy is Si In the light of the above statements, choose the correct answer from the options given below:
B. Both Statement I and Statement II are false
Statement I: The second ionization enthalpy of Ga is higher than that of Al. This is due to the poor shielding effect of the ten 3d electrons in Ga, which increases the effective nuclear charge and holds the valence electrons more tightly. The correct order of second ionization enthalpy is B > Ga > Al. Thus, Statement I is false. Statement II: The first ionization enthalpy generally decreases down the group. However, Pb has a slightly higher ionization enthalpy than Sn due to the poor shielding of 4f and 5d electrons (lanthanoid contraction). The correct order of first ionization enthalpy for Group 14 elements is Sn Both Statement I and Statement II are false. Answer: Both Statement I and Statement II are false
Related: Chemistry — Classification of Elements and Periodicity in Properties · All PYQ Banks