【化學】electron configurations

[訪客 purpledreamland]

Q: complete the electron configurations for Ni and Ni2+

Ni [Ar] 4s2 3d8

Ni2+ [Ar] 3d8

why is Ni2+ 3d8 but not 4s2 3d6.

Is it because 4s is still part of the 4 sub-shell???

extremely confused........T_T

[CKmonkey 10]

據說是因為丟電子是從最外層的軌域丟

而4s是最外層的軌域

[luadam4c 10]

For neutral atoms, the 4s orbital has similar energy with the 3d orbitals.

However, for cations, the energy level for the 3d orbitals are significantly reduced, more than that of the 4s orbital. That's why the 4s electrons are taken away before the 3d electrons.

Generally, what CKmonkey said holds true, as far as I know.