Air is an example of a mixture because the elements and compounds that make up air retain their individual properties. True or False
The correct answer and explanation is:
True
Air is a mixture because the components that make it up, such as nitrogen, oxygen, carbon dioxide, and other gases, retain their individual properties. A mixture is a physical combination of substances where each component keeps its own chemical identity and properties. This is distinct from a compound, where the substances combine chemically to form a new substance with different properties.
In the case of air, its components do not undergo any chemical reactions to form new substances. Instead, the gases simply exist together in a physical mixture, with each retaining its original characteristics. For example, nitrogen (about 78% of air) is inert, meaning it does not react easily with other gases, while oxygen (about 21%) supports combustion. These gases can be separated from each other by physical processes, such as fractional distillation, which is a method based on differences in boiling points.
Because the substances in air retain their chemical identities, air is classified as a mixture rather than a compound. This makes air a heterogeneous mixture, as its components are not chemically bonded and can be separated by physical means. However, due to the nature of the gases being uniformly distributed, air is often considered a homogeneous mixture in everyday use.
The physical properties of air are determined by the properties of its components, and changes to the amount of any of these components can alter the characteristics of air, such as its density and temperature. Thus, air exemplifies the concept of a mixture where individual components coexist without undergoing any chemical changes.