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The D-And-f-Block Elements
Question
Actinoid contraction is greater from element to element than lanthanoid contraction. Why?
Solution
In actinoids, 5f orbitals are filled. These 5forbitals have a poorer shielding effect than 4f orbitals (in lanthanoids). Thus, the effective nuclear charge experienced by electrons in valence shells in case of actinoids is much more that that experienced by lanthanoids. Hence, the size contaction in actinoids is greater as compared to that in lanthanoids.
Some More Questions From The d-And-f-Block Elements Chapter
In the series Sc (Z = 21) to Zn(Z = 30), the enthalpy of atomisation of zinc is the lowest i.e., 26, kJ mol. Why?
The E° (M2+/M) value for copper is positive (+ 0.34 V). What is possibility the reason for this?
How would you account for the irregular variation of ionisation enthalpies (first and second) in the first series of the transition elements?
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?
Which is a stronger reducing agent Cr2+ or Fe2+ and why?
Explain why Cu+ ion is not stable in aqueous solutions?
Actinoid contraction is greater from element to element than lanthanoid contraction. Why?
On what ground can you say that scandium (Z = 21) is a transition element but zinc (Z = 30) is not?
The outer electronic configuration of copper is 3d10 4s1, yet it is considered transition element. Why?
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Mock Test Series
Mock Test Series