the.com/chemical formula

means A notation that uses element symbols and numbers to show exactly which atoms, and how many of each, make up a substance.

from 'Chemical' traces back through French to Latin and Greek roots tangled up with 'alchemy' and possibly ultimately the ancient name for Egypt, 'Kemet' — the land of alchemical lore. 'Formula' is Latin for 'little form' or 'little rule,' a diminutive of 'forma' (shape, pattern). Chemists in the 19th century seized on 'formula' precisely because it meant a fixed, compact recipe — a small fixed pattern standing in for a fuller truth, which is exactly what H₂O does for water.