Steve_hi - 31-3-2013 at 02:53
http://education.jlab.org/elementbalancing/
http://www.youtube.com/watch?v=ABUDU4OwQk0
[Edited on 31-3-2013 by Steve_hi]
Steve_hi - 1-4-2013 at 10:05
Useful wallpaper
http://www.radiochemistry.org/periodictable/download_table.h...