Question
Question: Identify the incorrect statement among the following....
Identify the incorrect statement among the following.
The chemistry of various lanthanoids is very similar.
4f and 5f orbitals are equally shielded.
d-block elements show irregular and erratic chemical properties among themselves.
La and Lu have partially filled d orbitals and no other partially filled orbitals.
4f and 5f orbitals are equally shielded.
Solution
The decrease in the force of attraction exerted by the nucleus on the valency electrons due to presence of electrons in the inner shells is called shielding effect. An 4¦ orbital is nearer to the nucleus than 5¦ orbitals. In addition, the 20 electrons of 3d and 4d orbitals contribute the shielding to 4f electron while 44 electrons of 3d, 4d, 5d and 4f contribute the shielding to 5f. Hence shielding of 5¦ is more than 4f.