The letter square is 30 x 30, and it contains the names of all 103 chemical elements. They are spelled sideways, up and down, diagonally, and backwards. How many can you find?
Porter, Temple G.
"An Element Letter Square,"
Word Ways: Vol. 2
, Article 2.
Available at: https://digitalcommons.butler.edu/wordways/vol2/iss3/2