Topscore Question

[pkossak]

What is correct e- configuration for Zn2+?

answer is [Ar]4s0 3d10, but I thought it would be [Ar] 4s2 3d8 because 4s is lower energy than 3d. Anyone care to explain? Thanks a lot.

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[Cute Fairy]

What is correct e- configuration for Zn2+?

answer is [Ar]4s0 3d10, but I thought it would be [Ar] 4s2 3d8 because 4s is lower energy than 3d. Anyone care to explain? Thanks a lot.

1st write out the e configuration of the ground state which is 30 e. Then take out 2e from the valace shell because it is the outer most orbital and it would require less energy then taking e out of the 3rd orbital

hope it helps

 

[pkossak]

Thanks for the response.

That does makes sense, but I am still a little confused because wouldn't 4s2 fill before 3d10? So I figured it would be 2nd to lose e-.

 

[onelove4uk]

The reason you remove 2 from the s orbital is because half-filled and completely filled shells are very stable. Things like Zn and Fe are exceptions to the normal rule (there's a couple others too). Fe2+ for example goes from 4s2 3d6 to 4s1 3d5!
one electron removed from s and one removed from d to make 2 half-filled shells.