<http://schema.org/position>
"2"^^<http://www.w3.org/2001/XMLSchema#integer>
<http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_16%3A_The_Oxygen_Family/Chemistry_of_Sulfur>