Nothing says periodicity like neon and the other six noble gases. From top to bottom, they shore-up the whole right-hand side of the Periodic Table:
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At the very bottom right of the table is Ununoctium, the last noble gas. Only a few atoms of Uuo have been made, not enough to characterize in detail, but I'm sure that the properties of Uuo would make radon (Rn) look tame. Most transactinide elements are not of this earth.
Back to earth. Neon's colorful history and etymology are covered here by van der Krogt. The entire noble gas family eluded scientists for decades and for good reason. Interestingly, Neon's name was suggested by its discoverer's 13 year old child.
I think neon signs are cool. I didn't know until today that there's a Museum Of Neon Art (MONA) in Los Angeles link. I'll have to add it to my list of places to see.
*The name "Helium" is a bit of misnomer. It should called Helion. The suffix "ium" really and truly belongs to metallic elements. At the time of helium's discovery on the sun, it was assumed that helium was metallic.