.

Also know, do elements have a fixed composition?

Every sample of a given substance has the same properties because a substance has a fixed uniform composition. Why does an element have a fixed composition? An element has a fixed composition because it contains one type of atom. A compound is a substance that is made from two ore more simpler substances.

Additionally, why is air classified as a mixture? Because it is composed of various gases such as nitrogen, oxygen, carbon dioxide, inert gases and so on. Moreover , dust particles and water vapour are also present in the atmosphere because of which air is mixture.

Keeping this in consideration, is air a substance or mixture?

Answer and Explanation: Air is not a pure substance because it is a homogeneous mixture of different substances. Air is a homogeneous mixture because air is a thoroughly

Why is air not a substance?

Air isn't considered a pure substance because there is no one single chemical element of compound that forms air. Air is a mixture of various purechemical substances, most of which exist in the gaseous state.