Helppppp this makes no sense

Seawater is a mixture because it contains more than one element, meaning that it cannot be one element. it is not a compound because it is not composed of a fixed ratio of elements, and not all elements in it are chemically bonded to each other. also, components of a mixture can be separated via methods of physical separation, and this is true for sea water. hence, it is a mixture

an atom is a single basic unit of any matter. a molecule consists of two or more atoms bonded to each other chemically  in a fixed ratio