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प्रश्न
What is lanthanoid contraction? Write the.............
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उत्तर
The regular decrease in atomic and ionic radii from lanthanum to lutetium with increasing atomic number is called lanthanoid contraction.
Consequences :
The net result of the lanthanoid contraction is that the second and third d-series exhibit similar radii
Zr =160 pm
and Hf = 159pm
They have very similar physical and chemical properties.
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संबंधित प्रश्न
Explain effects of lanthanoid contraction.
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) \[\ce{Ho}\]
Match the property given in Column I with the element given in Column II.
| Column I (Property) | Column II (Element) | |
| (i) | Lanthanoid which shows +4 oxidation state |
(a) Pm |
| (ii) | Lanthanoid which can show +2 oxidation state |
(b) Ce |
| (iii) | Radioactive lanthanoid | (c) Lu |
| (iv) | Lanthanoid which has 4f7 electronic configuration in +3 oxidation state |
(d) Eu |
| (v) | Lanthanoid which has 4f14 electronic configuration in +3 oxidation state |
(e) Gd |
| (f) Dy |
On the basis of Lanthanoid contraction, explain the following:
Stability of the complexes of lanthanoids.
How would you account for the following:
There is a greater range of oxidation states among the actinoids than among the lanthanides.
The titanium (Z = 22) compound that does not exist is:-
Write any two consequences of Lanthanoid Contraction.
State a reason for the following:
La(OH)3 is more basic than Lu(OH)3.
Trivalent Lanthanoid ions such as La3+ (Z = 57) and Lu3+ (Z = 71) do not show any colour in their solution. Give a reason.
