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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
Account for the following :
Zr and Hf have almost similar atomic radii.
Compare the chemistry of actinoids with that of lanthanoids with special reference to electronic configuration.
Compare the chemistry of actinoids with that of the lanthanoids with special reference to chemical reactivity.
Write the different oxidation states of iron
Name an element of lanthanoid series which is well knwon to shown +4 oxidation state. Is it a strong oxidising agent or reducing agent?
Match the statements given in Column I with the oxidation states given in Column II.
| Column I | Column II | |
| (i) | Oxidation state of Mn in MnO2 is | (a) + 2 |
| (ii) | Most stable oxidation state of Mn is | (b) + 3 |
| (iii) | Most stable oxidation state of | (c) + 4 |
| Mn in oxides is | (d) + 5 | |
| (iv) | Characteristic oxidation state of lanthanoids is | (e) + 7 |
On the basis of Lanthanoid contraction, explain the following:
Trends in acidic character of lanthanoid oxides.
Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of ______.
State a reason for the following:
La(OH)3 is more basic than Lu(OH)3.
Assertion: There is a continuous increase in size among Lanthanoids with an increase in atomic number.
Reason: Lanthanoids do not show Lanthanoid contraction.
