One of the fun things about science is it allows people to be prophets without the need to grow a big beard and walk around the desert in a robe. True, Dmitri Mendeleev did have a big beard when he predicted the appearance of scandium—but he didn’t need it, and that’s the point.
Scandium is the Element That Was Prophesied. In fact, people went looking for it after the prophecy was publicized, because its prophet was so very respected. Dmitri Mendeleev’s periodic table looks very different from the modern one, and had only about sixty elements on it, but it was enough to make chemists understand that Mendeleev knew what he was talking about. Mendeleev was confident enough to make a number of predictions about as-yet undiscovered elements. Some predictions were vague, but when it came to one element he made extremely specific predictions.
The new element, which would be around 21 on the periodic table. It was so similar to boron that Mendeleev called it “ekaboron.” It would have an atomic weight of about 44. It would team up with oxygen at a ratio of about Eb2O3.” A single atom of ekaboron would combine with three atoms of chlorine, and make a very unstable combination. And a carbonate of ekaboron would not dissolve in water.
And lo, in 1879 the chemist Lars Nilson did find such a metal. While sorting through the two familiar substances gadolinite and euxenite, he found an element no one had ever knowingly encountered. It had an atomic weight of 45, but otherwise it was this mysterious, oxygen-loving boron-twin that everyone was talking about.
Nilson decided to call the element scandium, after Scandinavia. If I were him, I would have called it Mendeleevwasright, or possibly Holycrapine, but I suppose scandium is the name we’re stuck with.