${\text{4s}}^{\text{1}}{\text{\hspace{0.17em}3d}}^{\text{5}}$  is the valency electronic configuration of

For, chromium, Cr atomic number $Z=24$.

Electronic configuration of Cr is $\left[\text{Ar}\right]3{\text{d}}^{5}4{\text{s}}^1$.

Note: one electron from 4s orbital jumps to 3d orbital to get more stability by attaining half filled configuration  in 3d subshell.