Yes, in chemistry a pure substance means either an element or a compound. Thus, hydrogen, oxygen, sodium, iron, copper etc. are pure substances; and so are compounds such as water, sugar, ammonia, sodium chloride, methane, ethanol etc. A compound is composed of two or more elements combined in a fixed ratio by mass. Like an element, a compound also has a distinct chemical identity. A mixture is not a pure substance as it is a collection of two or more elements/compounds in varying ratio. Air, sea water, gasoline, vegetable oils, steel etc. are mixtures.
Hudson (CDP), Massachusetts. Hudson is a census-designated place (CDP) in the town of Hudson in Middlesex County, Massachusetts, United States. The population was 14,907 at the 2010 census.
Hudson, Ohio. Hudson is a city in Summit County, Ohio, United States. The population was 22,262 at the 2010 census. It is an affluent suburban community in the Akron Metropolitan Statistical Area and the larger ClevelandâAkronâCanton Combined Statistical Area, the 15th largest Combined Statistical Area in the United States.