Question

Identify the incorrect statement among the following

• A. $d$-Block elements show irregular and erratic chemical properties among themselves
• B. $La$ and $Lu$ have partially filled $d$- orbitals and no other partially filled orbitals
• C. The chemistry of various lanthanoids is very similar
• D. $4\,f$ and $5\,f$ orbitals are equally shielded

Answer 1

Answer: (D)

$4\,f$ and $5\,f$ orbitals are equally shielded

Answer 2

4f and 5f belongs to different energy levels, hence the shielding effect is on them is not the same. Shielding of 4f is more than 5f. Hence (4) is correct.