Assertion: The basic strength of oxides and hydroxides of lanthanoids decrease with increase in atomic number. Reason: The size of cation of lanthanoids increases with increase in atomic number.

Question

KollegeApply · Accepted Answer

If Assertion is CORRECT but Reason is INCORRECT. Explanation: The basic strength of oxides and hydroxides of lanthanoids decreases with an increase in atomic number due to lanthanoid contraction, which causes a decrease in ionic size. However, the reason is incorrect because the size of lanthanoid cations actually decreases, not increases, with an increase in atomic number.

AChoose Your Answer