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प्रश्न
Actinoid contraction is greater from element to element than the lanthanoid contraction, why?
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उत्तर
- Actinoid contraction is greater from element to element than lanthanoid contraction. The 5f orbitals in Actinoids have a very poorer shielding effect than 4f orbitals in lanthanoids.
- Thus, the effective nuclear charge experienced by electrons in valence shells in the case of actinoids is much more than that experienced by lanthanoids.
- In actinoids, electrons are shielded by 5d, 4f, 4d and 3d whereas in lanthanoids, electrons are shielded by 4d, 4f only.
- Hence, the size contraction in actinoids is greater as compared to that in lanthanoids.
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संबंधित प्रश्न
Which one of the following statements related to lanthanons is incorrect?
The most common oxidation state of actinoids is ____________.
What are inner transition elements?
Justify the position of lanthanides and actinides in the periodic table.
Compare lanthanoids and actinoids.
Out of Lu(OH)3 and La(OH)3 which is more basic and why?
Why do zirconium and Hafnium exhibit similar properties?
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.
The element with atomic number 57 belongs to ______.
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?
Electronic configurations of four elements A, B, C and D are given below:
(A) 1s22s22p6
(B) 1s22s22p4
(C) 1s22s22p63s1
(D) 1s22s22p5
Which of the following is the correct order of increasing tendency to gain electron:
