Respuesta :
A. The atmosphere
All the other examples are either elements or compounds, not mixtures. A mixture is a combination of elements that are not chemically or irreversibly conjoined so the atmosphere, made up of a variety of gases, would be a mixture.
All the other examples are either elements or compounds, not mixtures. A mixture is a combination of elements that are not chemically or irreversibly conjoined so the atmosphere, made up of a variety of gases, would be a mixture.