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प्रश्न
How would you account for the following:
There is a greater range of oxidation states among the actinoids than among the lanthanides.
Account for the following:
Actinoids show more number of oxidation states than lanthanoids.
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उत्तर
Actinides exhibit larger oxidation states than lanthanides because of the very small energy gap between 5f, 6d, and 7s subshells as compared to 4f, 5d, and 6s orbitals in the case of lanthanoids. Thus, the outermost electrons get easily excited to the higher energy levels, giving variable oxidation states.
संबंधित प्रश्न
What are chemical twins? Write ‘two’ examples.
Name a member of the lanthanoid series which is well known to exhibit +4 oxidation state.
Compare the chemistry of actinoids with that of the lanthanoids with special reference to chemical reactivity.
Name the members of the lanthanoid series which exhibit +4 oxidation state and those which exhibit +2 oxidation state. Try to correlate this type of behavior with the electronic configurations of these elements.
Explain, why lanthanum (Z = 57) forms La3+ ion, while cerium (Z = 58) forms Ce4+ ion?
Account for the following:
Zn, Cd and Hg are soft metals.
What is meant by Lanthanide contraction? Write the general electronic configuration of inner transition elements.
General electronic configuration of actinoids is `(n-2)f^(1-14)(n - 1)d^(0-2)ns^2`.Which of the following actinoids have one electron in 6d orbital?
(i) U (Atomic no. 92)
(ii) Np (Atomic no.93)
(iii) Pu (Atomic no. 94)
(iv) Am (Atomic no. 95)
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 |
Cerium (Z = S8) is an important member of lanthanoids. Which of the following statements about cerium is incorrect?
