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.
2 Square Miles of City. Hudson, New York, is located on the east side of the Hudson River in Columbia County, 120 miles north of New York City, 45 miles south of Albany and 160 miles west of Boston. The city is surrounded by the town of Greenport to the north, east and south, and by the Hudson River to the west.