Question

Identify the incorrect statement among the following:

(a) 4f and 5f orbitals are equally shielded.

(b) d-Block elements show irregular and erratic chemical properties among themselves.

(c) La and Lu have partially filled dorbitals and no other partially filled orbitals.

(d) The chemistry of various lanthanoids is very similar.

Answer 1

(a) : 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 4f orbital is nearer to the nucleus than 5f orbitals. Hence shielding of 4f is more than 5f.