-ium

Used to form the names of metal elements, after the style of early-named elements, as well as the isotopes of hydrogen.

Used to form the temporary systematic element name of a metallic or nonmetallic element which is postulated to exist, or which has been newly synthesized and has not yet been assigned a permanent name.

Used to form the name of polyatomic cations. Common examples are quaternary ammonium compounds used as neuromuscular blocking agents, cholinergic agents, anticholinergic agents, antibacterials/antiseptics, or other agents.

Appended to common words to create scientific-sounding or humorous-sounding fictional substance names.