Answer: Solitaire

In the 19th century, when Dmitri Mendeleev was struggling to organize the chemical elements in a practical and useful fashion, he began writing down all the known properties of each element on small note cards.

He would frequently arrange and rearrange these playing-card-sized notes into groupings like a player laying down columns of Solitaire cards. It was precisely these Solitaire-like columns that became the basis for the Periodic Table of Elements wherein elements are arranged in columns by atomic weight much like Solitaire cards are arranged by suit and value.

Mendeleev’s table, modified to include more recently discovered elements, is the same table we use today.