Dmitri Mendeleev might be long dead already, but his periodic table of elements - one of science's biggest contributions, is still working. It is still predicting elements we haven't yet discovered.

This TED-ed points out Mendeleev's periodic table is a ubiquitous sight in schools, on T-shirts, and in non-scientific spoofs. But the real deal is more than just an image: it's a deep and elegant organization of the elements.

In the 1870s, when Mendeleev devised his periodic table, there were only 56 known elements. Today, there are 118, and still countless more to be discovered. [TED-ed via NPR]