Actinides is the family of elements with atomic numbers 89 through 102. Actinium is the first in the series of actinides, and the family is named after it.
In 2367 the presence of actinides in the Ikalian asteroid belt made it difficult for the USS Enterprise-D to locate Kriosian rebels.
Comments
- The line in TNG: "The Mind's Eye" is from Kell, who says "The actinides in the asteroids provide effective protection from our sensors." Worf then nods in recognition of the problem. By the 24th century "actinides" must mean more than just the standard elements 89 through 102, else all it would take to frustrate Federation sensors would be to put a shield up of depleted uranium (another of the actinides). Supporting this is the fact that the International Union of Pure and Applied Chemistry (IUPAC) is currently recommending the name actinoid rather than actinide.