The electronic configuration of copper is

Atomic number of copper is  $\text{Z}=29$.

The electronic configuration of Cu is $\left[\text{Ar}\right]4{\text{s}}^{1}3{\text{d}}^{10}$.

Note: To get stable configuration copper is attained $4{\text{s}}^{1}3{\text{d}}^{10}$ instead of  $4{\text{s}}^{2}3{\text{d}}^9$. Because half filled or completely filled orbitals have more stable than other configurations.