3 posts • Page 1 of 1
Cr and Cu are exceptions to the ground state electron configurations rules. Normally, you would expect Cr to be [Ar]3d^4s^2, but it's actually [Ar]3d^54s^1. The reason why is because the Cr is more stable having 5 electrons in its d-orbital because then it's a half-filled subshell, compared to just 4 out of the 5 orbitals being filled, which would make it very unstable and reactive. So yes! You do take an electron from the s-orbital and transfer it to the d-orbital. The same logic applies to Cu, except its configuration will be [Ar] 3d^104s^1 because having a whole d-orbital filled is more stable.
Yea so to summarize, 3d^5 and 3d^10 have a lower Ionization energy than 4s^2 so we fill those shells first before adding electrons to the s-orbital. But for the rest of the atoms in that period you would first fill the s-orbital and then send electrons to the d-orbital.
Who is online
Users browsing this forum: No registered users and 1 guest