NEET2007Chemistryd and f Block ElementsActual
Identify the incorrect statement among the following:
Options
- ALanthanoid contraction is the accumulation of successive shrinkages
- BAs a result of lanthanoid contraction, the properties of 4 d series of the transition elements have no similar
- CShielding power of 4 f electrons is quite weak
- DThee is a decrease in the radii of the atoms or ions as one proceeds from La to Lu
Correct answer
B. As a result of lanthanoid contraction, the properties of 4 d series of the transition elements have no similar
Step-by-step solution
There is a steady decrease in the radii as the atomic number of the lanthanide elements increases. For every additional proton added in nucleus the corresponding electron goes to 4 f subshell. The shape of f -orbitals is very much diffused and they have poor shielding effect. The effective nuclear charge increases which causes the contraction in the size of electron charge cloud. This contraction in size is quite regular and known as Lanthanoid contraction. Since the change in the ionic radii in the lanthanide seri