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प्रश्न
Trivalent Lanthanoid ions such as La3+ (Z = 57) and Lu3+ (Z = 71) do not show any colour in their solution. Give a reason.
उत्तर
Many trivalent lanthanide ions are coloured in both solid and liquid forms because their f-orbitals are not fully filled. Lu+3 and La+3 are colourless in liquid form because they do not have any unpaired electrons.
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संबंधित प्रश्न
Write the electronic configurations of the elements with the atomic numbers 61, 91, 101 and 109.
What is lanthanoid contraction?
Account for the following:
Zn, Cd and Hg are soft metals.
What is Lanthanoid contraction?
Answer the followiiig questions:
Which trivalent ion has maximum size in the Lanthanoid series i.e. Lanthanum ion (La3+) to Luteium ion (Lu3+)?
(at. no. of Lanthanum = 57 and Lutetium = 71)
Name an element of lanthanoid series which is well knwon to shown +4 oxidation state. Is it a strong oxidising agent or reducing agent?
What is meant by Lanthanide contraction? Write the general electronic configuration of inner transition elements.
Match the compounds/elements given in Column I with uses given in Column II.
| Column I (Compound/element) | Column II (Use) | |
| (i) | Lanthanoid oxide | (a) Production of iron alloy |
| (ii) | Lanthanoid | (b) Television screen |
| (iii) | Misch metal | (c) Petroleum cracking |
| (iv) | Magnesium based alloy is constituent of | (d) Lanthanoid metal + iron |
| (v) | Mixed oxides of lanthanoids are employed | (e) Bullets |
| (f) In X-ray screen |
Why is Mn2+ ion more stable than Fe2+ ion?
(Atomic numbers of Mn = 25 and Fe = 26)
Mention alloy uses.
