Chemical Used to Clean Pool Water
This page is the CodyCross answer for the clue below from Mesopotamia, Group 971, Puzzle 4 (Achaemenid Empire).
Question is: Chemical Used to Clean Pool Water
and the answer is: CHLORINE
Word Meaning:
CHLORINE — A toxic, green, gaseous chemical element (symbol Cl) with an atomic number of 17.
Definitions from Wiktionary.