2.64 Among the following pairs of orbitals which orbital will experience the larger effective nuclear charge? (iii) 3d and 3p
Nuclear charge is defined as the net positive charge experienced by an electron in the orbital of an atom exerted by the nucleus of the atom.
Closer orbitals experience more nuclear charge than outer orbitals.
Therefore, (ii) 3d and 3p
The 3p orbital is more closer to the nucleus than 3d orbital hence 3p will experience a larger effective nuclear charge compared to 3d.