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प्रश्न
Compare the chemistry of actinoids with that of the lanthanoids with special reference to atomic and ionic sizes.
Compare the chemistry of actinoids with that of the lanthanoids in reference to atomic and ionic sizes.
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उत्तर
Both lanthanoids and actinoids show a decrease in the size of their atoms or ions in the +3 oxidation state. In lanthanoids this decrease is called lanthanoid contraction, while in actinoids it is called actinoid contraction. However, in actinoids, the contraction increases gradually due to the very low shielding effect of 5f-electrons from one element to another.
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संबंधित प्रश्न
Compare the chemistry of actinoids with that of lanthanoids with special reference to electronic configuration.
What are the consequences of lanthanoid contraction?
Account for the following:
Zn, Cd and Hg are soft metals.
Which trivalent ion has the maximum size in the Lanthanoid series, i.e., Lanthanum ion (La3+) to Luteium ion (Lu3+)?
(at. no. of Lanthanum = 57 and Lutetium = 71)
The f-block elements are known as ____________.
Gadolinium belongs to 4f series. It’s atomic number is 64. Which of the following is the correct electronic configuration of gadolinium?
Which of the following lanthanoids show +2 oxidation state besides the characteristic oxidation state +3 of lanthanoids?
(i) \[\ce{Ce}\]
(ii) \[\ce{Eu}\]
(iii) \[\ce{Yb}\]
(iv) \[\ce{Ho}\]
Although +3 oxidation states is the characteristic oxidation state of lanthanoids but cerium shows +4 oxidation state also. Why?
On the basis of Lanthanoid contraction, explain the following:
Radii of 4d and 5d block elements.
On the basis of Lanthanoid contraction, explain the following:
Trends in acidic character of lanthanoid oxides.
How would you account for the following:
There is a greater range of oxidation states among the actinoids than among the lanthanides.
Which of the following pairs has the same ionic size?
The titanium (Z = 22) compound that does not exist is:-
Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of ______.
Write any two consequences of Lanthanoid Contraction.
Write a note on lanthanoids.
Trivalent Lanthanoid ions such as La3+ (Z = 57) and Lu3+ (Z = 71) do not show any colour in their solution. Give a reason.
