Match the metals in Column II with their characteristic properties given in Column I. ( array |c|l|c|c| & Properties & & Metals A & Lanthanoid with low value of 3^ rd ionisation enthalpy. & P & V B & f-Block element with electronic configuration [ Rn ] 6 ~d ^2 7 ~s ^2 & Q & G d C & 3 ~d -series metal whose M ³⁺ _ ( aq ) is colourless. & R & T h D & 3 ~d -series metal with highest H _ ( atomisation ) & S & S c array )

Step-by-step solution

A: Gadolinium (Gd) has the electronic configuration [Xe] 4f^7 5d^1 6s^2 . The removal of the third electron from the 5d orbital is relatively easy because it results in a stable half-filled 4f^7 configuration. Thus, Gd has a low third ionisation enthalpy. So, A = Q. B: Thorium (Th) is an actinoid with the electronic configuration [Rn] 6d^2 7s^2 . So, B = R. C: Scandium (Sc) is a 3d -series metal with the electronic configuration [Ar] 3d^1 4s^2 . Its Sc³⁺ ion has the configuration [Ar] , which has no d -electrons (