Consider the ground state of Cu atom (Z = 29). The number of electrons with the azimuthal quantum numbers l = 1 and 2 are, respectively,

The electronic configuration of ${ }_{29}\mathrm{Cu}$ is $\left(1s{)}^2\right(2s{)}^2\left(2p{)}^6\right(3s{)}^2\left(3\mathrm{p}{)}^6\right(3\mathrm{d}{)}^{10}(4s{)}^1$

$/ =1$ corresponds top orbital. The number of electrons in p orbitals is 6 + 6 = 12 

$\mathrm{I} =2$corresponds to d orbital. The number of electrons in d orbitals is 10