The noble gasses should be split into helium, argon, krypton, radon, and xenon. They could be sparked to make neon, and radon would be radioactive. That would be sweet: radioactive gas. :)
Yah. Have you noticed that we use elements that cover most of the other elements' functions? As gas covered 99% flammable gases, METL covered 99% metals, and so on, and so on. Radioactive gas? I don't know. What usage other than as being 'sweet'? DMND covered all unmovable solids. DUST all burning powders, like sawdust or so.
sub menuses would proberbly be the way to go due to the infinitely expanding powder toy. Say if you put your mouse over nble, a sub category would pop up verticly and show all elements related to each other. But this really isn't needed at the moment, but in the future this would be reasonable.
but yeah, I'm with Dragonfree97 and boxmein on this one.