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Q. No.The lanthanide contraction is responsible for the fact that:
1. Zr and Y have about the same radius .
2. Zr and Zn have the same oxidation state.
3. Zr and Hf have about the same atomic radius .
4. Zr and Nb have a similar oxidation state.
The incorrect statement among the following is:
| 1. | There is a decrease in the radii of the atoms or ions as one proceeds from La to Lu. |
| 2. | Lanthanoid contraction is the accumulation of successive shrinkages. |
| 3. | As a result of lanthanoid contraction, the properties of the 4d series of the transition elements have no similarities with the 5d series of elements. |
| 4. | The shielding power of 4f electrons is quite weak. |
A pair among the following that have the same size is:
1. Fe2+, Ni2+
2. Zr4+, Ti4+
3. Zr4+ , Hf4+
4. Zn2+, Hf4+
The consequence(s) of lanthanoid contraction is/are :
| 1. | Similarity in the properties of second and third transition series. |
| 2. | Separation of lanthanoids is difficult. |
| 3. | Variation in the basic strength of lanthanide hydroxides. |
| 4. | All of the above. |
The reason for lanthanoid contraction is:
1. Negligible screening effect of 'f' orbitals
2. Increasing nuclear charge
3. Decreasing nuclear charge
4. Decreasing screening effect
Actinide contraction is
mainly related to:
1. Poor shielding by 5f subshell
2. Extraordinary decrement in Zeff
3. Both (1) and (2)
4. Strong shielding by 5f subshel
The three lanthanides that show a +2 oxidation state are:
1. Sm, Tb, Gd
2. Sm, Eu, Yb
3. La, Gd, Lu
4. Yb, Pm, Sm
The incorrect statement among the following regarding Cerium is :
| 1. | The +4 oxidation state of cerium is not known in solutions. |
| 2. | The +3 oxidation state of cerium is more stable than the +4 oxidation state. |
| 3. | The common oxidation states of cerium are +3, and +4. |
| 4. | Cerium (IV) acts as an oxidizing agent. |
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Q. No.
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