Chemistry - PERIODIC TABLE Question with Solution | TestHub
Statement-1: The atomic radii of elements in the second transition series (4d series) are very similar to those of the corresponding elements in the third transition series (5d series).
Statement-2: The effective nuclear charge experienced by the outermost electrons of 5d series elements is significantly reduced due to the strong shielding provided by the 4f electrons.
Options:
Answer:
Solution:
Statement-1: Due to the lanthanide contraction, the elements of the 5d transition series (after the lanthanides) have atomic radii very similar to their corresponding 4d series elements. For example, Zr and Hf have nearly identical atomic radii. Statement-1 is true.
Statement-2: The 4f electrons provide very poor shielding effect. This poor shielding leads to an increase in the effective nuclear charge experienced by the outermost electrons of the 5d series elements, causing the lanthanide contraction.
Therefore, the statement that effective nuclear charge is significantly reduced due to strong shielding by 4f electrons is false. Statement-2 is false.
