A compound is a chemical substance that forms when two or more different elements combine in a fixed ratio. Water (H2O), for example, is a compound that is made up of two hydrogen atoms for every one oxygen atom. Sodium chloride (NaCl) is a compound made up of one sodium atom for every chlorine atom.
Hudson, Iowa. Hudson is a city in Black Hawk County, Iowa, United States. The population was 2,282 at the 2010 census. The rural community of Hudson has grown in recent years and is included as a part of the Waterloo-Cedar Falls Metropolitan Statistical Area. Contents.
Nestled between the Catskill and Berkshire Mountains in Columbia County, Hudson is just 120 miles north of New York City, 45 miles south of Albany, and 160 miles west of Boston.