Chalcogens, Pnictogens

A pnictogen is an element from Group V of the Periodic Table; a chalcogen is one from Group VI. The etymology fascinates. 'Chalcogen' comes from Greek chalkos, which means 'copper'; 'pnictogen' comes from Greek ta pnikta, which means 'those which are choked'.

Why so odd? Well, to a metallurgist, many of the copper ores are compounds of copper and oxygen or sulfur; copper finds many ways to bond with the chalcogens. Pnictogens include nitrogen and phosphorus — elements which, in their molecular forms, either smother by substitution of oxygen or by combination with oxygen.