Here's a new YouTube channel from Nottingham University in the UK -- here, scientist-vloggers are in the process of posting a video for each element of the periodic table. Sort of "Mythbusters" meets chemistry, with real live awesome mad scientist hair. This is one of the neatest, most clever, and most enduringly valuable things I've seen on YT in a while.
Periodic Table of Videos channel, and The "sodium" video, above, is a good place to start.
[ YouTube, thanks Mark "coolest Scottish dude in Silicon Valley" Day ]