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)1s22s22p63s23p63d104s24p6

Explanation:

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

2.8.18.8.22.8.18.8.2

In orbital notation this is:

1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)4s^(2)4p^(6)5s^(2)1s22s22p63s23p63d104s24p65s2

The noble gas shorthand notation is:

[Kr]5s^(2)[Kr]5s2

When strontium forms a 2+ ion the 2 outer 5s5s electrons are lost so Sr^(2+)Sr2+ can be written as:

1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)4s^(2)4p^(6)1s22s22p63s23p63d104s24p6

Or:

[Kr][Kr]