Scientists at University of Nottingham made a page with all chemical elements commented in video by researchers. They explain in very easy non-technical short videos a little about history and properties of each element in the periodic table. They also made a cool page with sixty symbols of physics and astronomy . Though not all symbols presented there are mathematical symbols they represent one specific major event or feature in physics or astronomy. By the way, the video about the infinity symbol is amazing.
Enjoy it!
www.periodicvideos.com
www.sixtysymbols.com