Classify each of the following as a pure substance, a solution, or a heterogeneous mixture:
a gold ingot
We are asked to classify a gold ingot as a pure substance, a solution, or a heterogeneous mixture.
Recall that mixtures are combinations of two or more pure substances (elements or compounds).
Mixtures are not chemically combined.
Mixtures can either be:
• Homogeneous: the components are evenly distributed and indistinguishable from each other (e.g. solution)
• Heterogenous: the components are not evenly distributed and distinguishable from each other
In chemistry, a pure substance is a sample of matter with both definite and constant composition and distinct chemical properties.
Examples of pure substances include chemical elements and compounds. Alloys and other solutions may also be considered pure if they have a constant composition.