Question

What is a mixture or an impure substance

Answer 1

A mixture is an impure substance. It consists of different elements andsubstances combined together physically in an unknown ratio. Mostlymixtures are heterogenous. Their constituents are not combined chemically but only physically.

Answer 2

A mixture is a material system made up of two or more different substances which are physically mixed but are obtained chemically.

Or

The mixtures are products of mechanical mixing of elements are compounds without chemical bonding so that each component substance retains its own chemical properties.