# Mercury Hg2+2 ion

1. ### Cesium

274
Mercury can form Hg2+2 and Hg+2 ions. Why does mercury form Hg2+2? Are there any other "diatomic ions" like this? I assume this has to do with atomic size, but why don't zinc and cadmium behave like this? They only form Zn+2 and Cd+2.

Last edited: Mar 15, 2005
2. ### chem_tr

613
Hg+ atom has sp hybrid orbital, so it likes to bond with additional Hg+ ion to form a Hg22+ ion. Copper(I) ions are said to form such bonding, but I am not sure about this. Also some atoms in which organometallic bonding principles are present (like Mn2(CO)10) has Mn-Mn bonding to reach a stable noble gas configuration.

Last edited: Mar 16, 2005