## Ground state elec. config.

Jimmy lira-1G
Posts: 61
Joined: Fri Apr 06, 2018 11:03 am

### Ground state elec. config.

Give the ground state electron configuration for the following:

Sn^ 4+

- I did this practice problem, but I got
[Kr]5s^2 5p^2 4d^10
However i know we have to take away the 4+ , but how do I know which to take it from ? why can't I take it away from the d ?

Jimmy Lira 1-G

Cindy Nguyen 1L
Posts: 48
Joined: Fri Apr 06, 2018 11:04 am

### Re: Ground state elec. config.

You take away the electrons from the outer shell (the valence electrons). In this case, the electrons in the s and p orbitals are the outermost electrons.

Isabelle De Rego 1A
Posts: 40
Joined: Fri Apr 06, 2018 11:02 am

### Re: Ground state elec. config.

If this helps: The n, if it is higher that means that it is farther away, although it's energy level may be lower. For example, 3d is closer than 4s, but it's energy level is higher.

Joanna Pham - 2D
Posts: 113
Joined: Fri Apr 06, 2018 11:04 am

### Re: Ground state elec. config.

For ground state electron, you need to order the subshells from lowest to highest energy first, so the electron configuration of Sn would be [Kr] 4d^10 5s^2 5p^2. When it's written this way, it's easier to see which subshell, at least for me, the electrons are removed from, which is outermost shell (the p-shell in this case). So for the configuration of Sn+4, you would take away the electron from the 5p subshell first then another two electrons from the 5s subshell. Hope this helps!