Answer:
Ba^2+
Explanation:
The element Barium has electronic configuration; 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2.
It is a member of group 2 in the periodic table hence it forms a divalent ion Ba^2+.
When the outermost 6s2 electron is removed, we have the ion whose configuration is; 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6.
