Accurentum

From Memory Alpha, the free Star Trek reference

Name:	Acurentum
Symbol:	Ac
Atomic Number:	Unknown
Atomic Weight:	118

Accurentum is a chemical element listed on the Table of Elements. (TNG: "Rascals")

The element Accurentum had the symbol "Ac" which is the same atomic symbol used for Actinium. Named after the AC electric current which is about 118V in the United States.