# Electron configuration

1. Nov 7, 2008

### jupiter_8917

Write the electron configuration of Cd2+

Is It right if I write it like this 1s^2 2s^2 2p^6 3s^1 3p^6 3d^10 4s^2 4p^6 5s^2 4d^10???

Can anyone please correct me if it is wrong??? Thank you very much!!!!

2. Nov 7, 2008

### Staff: Mentor

5s24d10 looks to me like neutral atom, not a cation.

Why 3s1? Is it just a typo?

3. Nov 7, 2008

### lucky_star

Hi,
In order for Cd to form Cd2+, Cd has to lose its 2e- in the outer-shell. So, take a look at your configuration, you are having the configuration for the neutral Cd, you need to remove 2 outer e- to get the right configuration. And also don't forget the "reminder" from Mr. Borek about the 3s1 typo.

Good Luck!

4. Nov 7, 2008

### jupiter_8917

do you mean it need to be like this in order to form Cd2+????? 1s^2 2s^2 2p^6 3s^1 3p^6 3d^10 4s^2 4p^6

thanks again,

5. Nov 8, 2008

### Staff: Mentor

Sorry for the confusion. Electron configuration of Cd can be given as [Kr]5s24d10 - that is very convenient short hand notation, that uses noble gas configuration as its basis. Configuration of Kr is 1s22s22p63s23p64s23d104p6, so [Kr]5s24d10 means 1s22s22p63s23p64s23d104p65s24d10 - that's configuration of neutral Cd atom. I was referring to this notation and just to the last two subshells.

[Kr]5s24d10 is a configuration of the neutral atom. As it was said several times - to make Cd2+ you have to remove two electrons.

Last edited: Nov 8, 2008