Match the property given in Column I with the element given in Column II.
| Column I (Property) |
Column II (Element) |
||
|---|---|---|---|
| A. | Lanthanoid which shows +4 oxidation state | 1. | Pm |
| B. | Lanthanoid which can show +2 oxidation state | 2. | Ce |
| C. | Radioactive lanthanoid | 3. | Lu |
| D. | Lanthanoid which has $4f^7$ electronic configuration in +3 oxidation state | 4. | Eu |
| E. | Lanthanoid which has $4f^{14}$ electronic configuration in +3 oxidation state | 5. | Gd |
| 6. | Dy |
A. $\rightarrow(2)$ B. $\rightarrow$ (4) C. $\rightarrow$ (1) D. $\rightarrow(5)$ E. $\rightarrow$ (3)
A. Lanthanoid which shows +4 oxidation state is cerium.
${ }_{58} \mathrm{Ce}=[\mathrm{Xe}] 4 f^2 5 d^0 6 \mathrm{~s}^2 ;$ Oxidation state $=+3,+4$
B. Lanthanoid which can show +2 oxidation state is europium.
${ }_{63} \mathrm{Eu}=[\mathrm{Xe}] 4 f^7 5 d^0 6 \mathrm{~s}^2$; Oxidation state $=+2,+3$
C. Radioactive lanthanoid is promethium. It is the only synthetic (man-made) radioactive lanthanoid.
D. Lanthnoid which has $4 f^7$ electronic configuration in +3 oxidation state is gadolinium.
${ }_{64} \mathrm{Gd}=[\mathrm{Xe}] 4 f^7 5 d^1 6 s^2$; Oxidation state $=+3$
E. Lanthanoid which has $4 f^{14}$ electronic configuration in +3 oxidation state is lutetium
${ }_{71} \mathrm{Lu}=[\mathrm{Xe}] 4 f^{14} 5 d^1 6 s^2 ;$ Oxidation state $=+3$
Match the properties given in Column I with the metals given in Column II.
| Column I (Property) |
Column II (Metal) |
||
|---|---|---|---|
| A. | Element with highest second ionisation enthalpy | 1. | Co |
| B. | Element with highest third ionisation enthalpy | 2. | Cr |
| C. | M in M(CO)$_6$ is | 3. | Cu |
| D. | Element with highest heat of atomisation | 4. | Zn |
| 5. | Ni |
A. $\rightarrow(3)$ B. $\rightarrow$ (4) C. $\rightarrow(2)$ D. $\rightarrow$ (1)
A. $\mathrm{Cu}^{+}=3 d^{10}$ which is very stable configuration due to full-filled orbitals. Hence, removal of second electron requires very high energy.
B. $\mathrm{Zn}^{2+}=3 d^{10}$ which is very stable configuration. Hence, removal of third electron requires very high energy.
C. Metal carbonyl with formula $\mathrm{M}(\mathrm{CO})_6$ is $\mathrm{Cr}(\mathrm{CO})_6$.
D. Nickel is the element with highest heat of atomisation.
Assertion $(\mathrm{A}) \mathrm{Cu}^{2+}$ iodide is not known.
Reason $(\mathrm{R}) \mathrm{Cu}^{2+}$ oxidises $\mathrm{I}^{-}$to iodine.
Assertion (A) Separation of Zr and Hf is difficult.
Reason (R) Because Zr and Hf lie in the same group of the Periodic Table.
Assertion (A) Actinoids form relatively less stable complexes as compared to lanthanoids.
Reason (R) Actinoids can utilise their $5 f$ orbitals alongwith 6d orbitals in bonding but lanthanoids do not use their 4 f orbital for bonding.