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प्रश्न
Why do zirconium and Hafnium exhibit similar properties?
उत्तर
- The element of the second and third transition series resemble each other more closely than the elements of the first and second transition series due to lanthanoid contraction.
- e.g., Zr – 4d series -Atomic radius 145 pm Hf – 5d series – Atomic radius 144 pm
- The radii are very similar even though the number of electrons increases.
- Zr and Hf have very similar chemical behaviour, having closely similar radii and electronic configurations.
- Radius-dependent properties such as lattice energy, solvation energy are similar.
- Thus lanthanides contraction leads to the formation of pair of elements and those known as chemical twins, e.g., Zr – Hf
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संबंधित प्रश्न
Write the general outer electronic configuration of f- block elements.
Assertion: Ce4+ is used as an oxidizing agent in volumetric analysis.
Reason: Ce4+ has the tendency of attaining +3 oxidation state.
The most common oxidation state of actinoids is ____________.
Which one of the following is not correct?
What are actinoids? Give three examples.
Compare lanthanoids and actinoids.
Actinoid contraction is greater from element to element than the lanthanoid contraction, why?
Which of the following is not an actinoid?
In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz, s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Arfbau principle, the seven periods have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the main body of the periodic table.
Which of the elements whose atomic numbers are given below, cannot be accommodated in the present set-up of the long form of the periodic table?
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: Size of Bk3+ ion is less than Np3+ ion.
Reason R: The above is a consequence of the lanthanoid contraction.
In the light of the above statements, choose the correct answer from the options given below:
