# What is the noble gas configuration of chromium (Cr), atomic number 24?

$C r : \left[A r\right] 4 {s}^{1} 3 {d}^{5}$
This is an anomalous configuration, something silly that you shouldn't be tested on, in my opinion. However, the reason for this specific configuration is that chromium is more stable with half filled $4 s$ and $3 d$ orbitals than only a 40% full $3 d$ orbital.