Instructional Video6:21
SciShow

The Nuclear-Powered Clocks of the Future

12th - Higher Ed
Atomic clocks are the best timekeepers humanity's got these days, but scientists are working toward something even better: a SUB-atomic (aka nuclear) clock.
Instructional Video
University of Nottingham

University of Nottingham: Periodic Table of Videos: Actinium

9th - 10th
Actinium is a very radioactive and dangerous element as you will hear about in this video. [4:36]