$\left[\text{Ar}\right]4{\text{s}}^{2}3{\text{d}}^5$  is the electronic configuration of

Solution: Atomic number of Argon (Ar) is  $Z=18$.

Total number of electrons with the electronic configuration $\left[\text{Ar}\right]4{\text{s}}^{2}3{\text{d}}^5$ is

$18+2+5=25$. Therefore, the name of an element with electron configuration $\left[\text{Ar}\right]4{\text{s}}^{2}3{\text{d}}^5$  is manganese, Mn.