{warning} Since version 21.2 alkali metals and alkaline earth metals are no longer assigned a default valence. They are imported from MDL mol V2000 and V3000 files with zero valence unless defined otherwise in the file

Default valence of metal atoms

Metal atoms are exported with their valence electrons into MDL mol format.

Consequently, 1 or 2 implicit hydrogens are added to the alkali metals and alkaline earth metals upon export.

By default Tin(Sn) is exported with 2 valence electrons and Thallium (Tl) with one.

{info} You can set a non-default valence using the Atom menu or the Atom pop-up menu.

Above : Metals exported to MDL mol file using default settings.

Above: Metals in MarvinSketch.