Electron configuration from vanadium to chromium? [duplicate]








**This question already has answers here**:
 
 




[Why do elements in columns 6 and 11 assume 'abnormal' electron configurations?](/questions/151/why-do-elements-in-columns-6-and-11-assume-abnormal-electron-configurations)

 (4 answers)
 


[Ground state electron configuration of chromium [duplicate]](/questions/9145/ground-state-electron-configuration-of-chromium)

 (2 answers)
 

Closed 6 years ago.



The electron configurations for vanadium is: $\ce{1s^2 2s^2 2p^2 3s^2 3p^6 3d^3 4s^2}$, and the electron configuration for chromium is: $\ce{1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^1}$.


In looking at the electron configurations of two consecutive elements, I noticed that an electron in the $\ce{4s}$ orbital "jumped" to the higher energy $\ce{3d}$ orbital. Why is this so? 


