The story
- Proto-Indo-European*pénkʷe
- Proto-Hellenic*pénkʷe
- Ancient Greekπέντε (pénte)
- Ancient Greekπεντᾰ- (pentă-)
- Englishpenta-
- Englishphosphorylated
- English todaypentaphosphorylated
From penta- + phosphorylated.
Etymology from Wiktionary, CC BY-SA 4.0.