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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
Define lanthanoid contraction.
What are chemical twins? Write ‘two’ examples.
Compare the chemistry of actinoids with that of the lanthanoids with special reference to chemical reactivity.
Write the electronic configurations of the elements with the atomic numbers 61, 91, 101 and 109.
Account for the following:
Zn, Cd and Hg are soft metals.
What is the action of the following on lanthanoids?
a. water
b. Sulphur, heat
c. nitrogen, heat
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 is the characteristic oxidation state for lanthanoids but cerium also shows +4 oxidation state because:
(i) it has variable ionisation enthalpy
(ii) it has a tendency to attain noble gas configuration
(iii) it has a tendency to attain f 0 configuration
(iv) it resembles Pb4+
The lathanide ion that would show colour is ______.
Which one of the lanthanoids given below is the most stable in divalent form?
