tennessium

== English == === Noun === tennessium (uncountable) A rejected name for tennessine ==== Usage notes ==== According to IUPAC guidelines in place in 2010, when said element was discovered, all new elements should have names ending in -ium. However, by the time tennessine was named (2016), IUPAC had changed its mind, hence the name tennessine, rather than tennessium. ==== See also ==== oganessium