1. | 4f orbitals are penultimate |
2. | 4f orbitals have a greater shielding effect |
3. | 5f orbitals have a poor shielding effect |
4. | 5f orbitals have a greater shielding effect |
Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of:
1. | Lanthanoid contraction |
2. | Having similar chemical properties |
3. | Belonging to the same group |
4. | Diagonal relationship |
Identify the incorrect statement from the following:
1. | Zirconium and Hafnium have identical radii of 160 pm and 159 pm, respectively as a consequence of lanthanoid contraction. |
2. | Lanthanoids reveal only +3 oxidation state. |
3. | The lanthanoid ions other than the f0 type and the f14 type are all paramagnetic. |
4. | The overall decrease in atomic and ionic radii from lanthanum to lutetium is called lanthanoid contraction. |
A pair among the following have nearly the same atomic radii:
(Numbers in the parenthesis are atomic numbers).
The reason for the lanthanoid contraction is:
1. negligible screening effect of 'f' orbitals.
2. increasing nuclear charge.
3. decreasing nuclear charge.
4. decreasing screening effect.
1. | The greater metallic character of the lanthanoids than that of the corresponding actinoids. |
2. | More energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals. |
3. | The lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals. |
4. | More active nature of the actinoids. |
Which of the following ions will exhibit colour in aqueous solutions?
1. La3+ (Z=57)
2. Ti3+ (Z=22)
3. Lu3+ (Z=71)
4. Sc3+ (Z=21)
Identify the incorrect statement among the following:
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. |
Lanthanoids are:
1. | 14 elements in the seventh period (atomic no. = 90 to 103) that are filling 5f sublevel. |
2. | 14 elements in the sixth period (atomic no. 58 to 71) that are filling 4f sublevel |
3. | 14 elements in the seventh period (atomic no. = 58 to 71) that are filling 4f sublevel |
4. | 14 elements in the sixth period (atomic no. 90 to 103) that are filling 4f sublevel |