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प्रश्न
Give reason for the following statement:
Physical and chemical properties of the 4d and 5d series of the transition elements are quite similar to expected.
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उत्तर
Physical and chemical properties of 4d and 5d series elements are similar because they have same atomic and ionic radii due to the lanthanide contraction. Due to equal atomic radii the size of Zr and Hf, Nb and Ta, Mo and W, etc., the two elements of each pair have the same properties.
संबंधित प्रश्न
Why is Sc3+ colourless while Ti3+ coloured? (Atomic number Sc = 21, Ti =22)
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?
To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.
Why do transition elements show variable oxidation states ? In 3d series (Sc to Zn), which elements shows the maximum number of oxidation state and why ?
When \[\ce{KMnO4}\] solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because ______.
Although Zirconium belongs to 4d transition series and Hafnium to 5d transition series even then they show similar physical and chemical properties because ______.
Match the solutions given in Column I and the colours given in Column II.
| Column I (Aqueous solution of salt) |
Column II (Colour) |
| (i) \[\ce{FeSO2.7H2O}\] | (a) Green |
| (ii) \[\ce{NiCl2.4H2O}\] | (b) Light pink |
| (iii) \[\ce{MnCl2.4H2O}\] | (c) Blue |
| (iv) \[\ce{CoC12,6H2O}\] | (d) Pale green |
| (v) \[\ce{Cu2 Cl2}\] | (e) Pink |
| (f) Colourless |
Which of the following maxm magnetic moment?
Why Zn, Cd and Hg are not called transition metals?
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
