Actinide

The actinide series 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.

The spaceborne organism nicknamed "Junior", discovered by the USS Enterprise (NCC-1701-D) in 2367, had an outer shell made from silicates, actinides, and carbonaceous chondrite. 

In 2367, Klingon Ambassador Kell and Lieutenant Worf discussed a tactical situation, they concluded that the presence of actinides in the Ikalian asteroid belt made it difficult for the Enterprise-D to locate Kriosian rebels. 

Actinides

 * #90 Thorium (Th)


 * #92 Uranium (U)


 * #94 Plutonium (Pu)


 * #98 Californium (Cf)