Diquat
Herbicides
Paraquat
Ethane
Ethane is an organic compound, specifically a hydrocarbon (aliphatic alkane), with the chemical formula C2H6, which consists of two carbon atoms and six hydrogen atoms, and is the second simplest alkane after methane. However, it's important to note that ethane is not a medical term or concept; it's a basic chemistry term.
Pyridinium Compounds
Puerto Rico
An island in the Greater Antilles in the West Indies. Its capital is San Juan. It is a self-governing commonwealth in union with the United States. It was discovered by Columbus in 1493 but no colonization was attempted until 1508. It belonged to Spain until ceded to the United States in 1898. It became a commonwealth with autonomy in internal affairs in 1952. Columbus named the island San Juan for St. John's Day, the Monday he arrived, and the bay Puerto Rico, rich harbor. The island became Puerto Rico officially in 1932. (From Webster's New Geographical Dictionary, 1988, p987 & Room, Brewer's Dictionary of Names, 1992, p436)