NEETChemistryd and f Block Elements
Match the column : ( array |l|l|l|l| & Column I & & Column II & (Property) & & (Element) (i) & array l Lanthanoid which show +4 oxidation state array & (a) & Pm (ii) & array l Lanthanoid which can show +2 oxidation state array & (b) & Gd (iii) & Radioactive lanthanoid & (c) & Ce (iv) & array l Lanthanoid which has 4 f ^7 configuration in +3 oxidation state array & (d) & Eu array )
Options
- Ai-a, ii-b, iii-c, iv-d
- Bi-c, ii-d, iii-b, iv-a
- Ci-c, ii-d, iii-a, iv-b
- Di-b, ii-c, iii-d, iv-a
Correct answer
C. i-c, ii-d, iii-a, iv-b
Step-by-step solution
(i) Lanthanoid which shows +4 oxidation state: Answer: (c) Ce Cerium (Ce) is the only lanthanoid that can exhibit a +4 oxidation state. This is due to its relatively low ionization energy for the fourth electron. (ii) Lanthanoid which can show +2 oxidation state: Answer: (d) Eu Europium (Eu) can exhibit a +2 oxidation state. This is because the half-filled (4 f⁷ ) configuration provides extra stability. (iii) Radioactive lanthanoid: Answer: (a) Pm Promethium (Pm) is the only radioactive lanthanoid found in nature.