Multiple choice

Assertion (A): 4f and 5f orbitals are equally shielded. Reason (R): As a result of lanthanide contraction, the properties of 4d series of the transition elements have no similarities with the 5d series of elements.

In the following question there are two statements, Assertion (A) and Reason (R). Consider both the statements independently and mark your answer:
1. If A and R both are correct and R is correct explanation of A.
2. If A and R both are correct and R is not correct explanation of A.
3. If A is correct and R is incorrect.
4. If A is incorrect and R is correct.
5. If A and R both are incorrect.

  1. 1

  2. 2

  3. 3

  4. 4

  5. 5
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

4f orbital electrons are shielded more than 5f orbital electrons. The atomic radii of 4d and 5d elements down the group become quite similar due to lanthanide contraction. Due to the similarity in the size of the elements of the two series, the elements of 2nd (4d series) and 3rd series (5d series) resemble each other more closely that do the elements of the 1st (3d series) and 2nd transition series (4d series).

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