What is the electron configuration of Sr2+?

1 Answer
Oct 17, 2015

#1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)4s^(2)4p^(6)#

Explanation:

Strontium is atomic number 38 so its electron configuration can be written:

#2.8.18.8.2#

In orbital notation this is:

#1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)4s^(2)4p^(6)5s^(2)#

The noble gas shorthand notation is:

#[Kr]5s^(2)#

When strontium forms a 2+ ion the 2 outer #5s# electrons are lost so #Sr^(2+)# can be written as:

#1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)4s^(2)4p^(6)#

Or:

#[Kr]#