When you go to the D's you go back... So it'd be :
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^2
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^2
What Is The Electron Configuration Of Zirconium?
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 4d^10 4p^6 5s^2 5d^2