Mendeleev's predicted elements
Dmitri Mendeleev published a periodic table of the chemical elements in 1869 based on properties that appeared with some regularity as he laid out the elements from lightest to heaviest. When Mendeleev proposed his periodic table, he noted gaps in the table and predicted that as-then-unknown elements existed with properties appropriate to fill those gaps. He named them eka-boron, eka-aluminium and eka-silicon with atomic masses 44, 68 and 72 respectively.
Tables (board game)
The τάβλη of Zeno's time is believed to be a direct descendant of the earlier ancient Roman "Ludus duodecim scriptorum" ("game of twelve lines" or, better, "game of twelve signs") with that board's middle row of points removed, and only the two outer rows remaining. Ludus duodecim scriptorum used a board with three rows of 12 points each, and the pieces were moved across all three rows according to the roll of three dice. The earliest known mention of the game is in Ovid's "Ars Amatoria" ("The Art of Love") (written between 1 BC and 8 AD).
In the 11th century Shahnameh, the Persian poet Ferdowsi credits Burzoe with the invention of "nard" in the 6th century. He describes an encounter between Burzoe and a Raja visiting from India. The Raja introduces the game of chess, and Burzoe demonstrates nard, played with dice made from ivory and teak.