Holy Praseodymium Batman; what the heck is Gadolinium

I was looking for a site in my favorites, and noticed that JR had saved a site which has an interactive Periodic Table of Elements. Just for yucks I went to check it out. I know it's been a long time since I looked at the table; but I could not believe how many of the elements there were that I had no idea even existed. I don't know that I could have named more than dozen. Take for instance, Ununnilium---it's man made, and there are no known uses. Why put it in there, other than giving an opportunity to sadistic science teachers to mess with their students on exams.