What term describes the structure of a substance?

The correct answer, "Composition," refers to the specific arrangement and types of components that make up a substance. It encompasses both the identity of the elements or compounds present and their proportions within that substance, highlighting how these factors contribute to its overall structure and properties. Understanding composition is crucial in fields like chemistry and materials science, as it allows scientists to predict how a substance will behave in different environments or reactions.

Density, while related to the structure of a substance, specifically refers to the mass per unit volume and does not capture the intricacies of what the substance is made of. Matter is a broader term that covers anything that has mass and takes up space, but it does not detail the internal arrangement of a substance. The term particle often refers to the small constituents of matter, such as atoms and molecules, but does not adequately describe the substance's overall structure or composition. Therefore, "Composition" is the most precise term for describing the structure of a substance.