Fixed the periodic table entry
Fixed the periodic table entry

This went missing with the menu builder changes.

Change-Id: If019d06596cb94c575a0d10531fe4af6587928fd

OpenChemistry/avogadroapp,wadejong/avogadroapp,wadejong/avogadroapp,OpenChemistry/avogadroapp,ghutchis/avogadroapp,wadejong/avogadroapp,ghutchis/avogadroapp,ghutchis/avogadroapp,OpenChemistry/avogadroapp,OpenChemistry/avogadroapp,ghutchis/avogadroapp