For a 4d orbital, n (principal quantum number )=4 l (azimuthal quantum number) =2 since for d-orbital, l=2 m (magnetic quantum number) ranges from −l tol, i.e. from −2 to +2
s (spin quantum number) can be +
1
2
or −
1
2
. So, set of quantum number for 4d-electrons are 4 ,2,1 and