Which of these is NOT a real element of the periodic table?

While some elements like Flerovium and Tennessine may sounds strange, they do appear on the Periodic Table of Elements. Unobtanium, however, does not. That comes from the world of the Avatar movies, where it is the name of a resource that humans and Na'vi fight over.

Asked by Ben Jenkins · Last updated 2 years ago · 32.3K views