Match the property given in Column I with the element given in Column II.

Answer

A. `rarr (2)` B. `rarr (4)` C. `rarr (1)` D. `rarr (5)` E. `rarr (3)`

Explanation

A. Lanthanoid which shows `+4` oxidation state is cerium.
`_(58)Ce = [Xe] 4f^(2) 5d^(0) 6s^(2)`, Oxidation state = + 3, + 4
B. Lanthanoid which can show + 2 oxidation state is europium.
`._(63)Eu=[Xe]4f^(7) 5d^(0) 6s^(2)`, Oxidation state = + 2, + 3
C. Radioactive lanthanoid is promethium. It is the only synthetic (man-made) radioactive lanthanoid.
D. Lanthnoid which has `4f^(7)` electronic configuration in +3 oxidation state is gadolinium.
`_(64)Gd = [Xe] 4f^(7) 5d^(1) 6s^(2)`, Oxidation state = +3
E. Lanthanoid which has `4f^(14)` electronic configuration in +3 oxidation state is lutetium
`._(71)Lu = [Xe] 4f^(14)5d^(1)6s^(2)`, Oxidation state = +3