What is it called when something is observed without the chemical makeup being changed?

Answer 1

Asked and answered. It's called a physical change.

Answer 2

First, "when something is observed" might better be worded as "when a property of some material (or substance) is observed to change."

Second, it is difficult to observe the "chemical makeup" of a substance, that is, the atoms in a molecule of that substance, "being changed." Chemists primarily recognize substances by difference in their physical properties (once the materials have been separated into pure substances). They secondarily recognize materials by how they interact (react) with other (pure) substances. The latter interactions (reactions) are chemical properties.

So, we are looking at changes in a material that do not affect the "chemical makeup" of the material. By default, we are looking at physical changes because in a chemistry course we distinguish between two types of changes: physical changes and chemical changes.

Physical changes are most usefully observed in physical properties of material when a material is isolated from other materials, that is, in the properties of pure substances. Chemical changes are observed when (typically) two or more (pure) substances are mixed and interact (react) to form additional materials. After separation, each of the materials is usually identified by its physical properties, such as, color, density, melting point, boiling point, and phase present at any temperature (at atmospheric pressure). Physical properties are not affected by the amount of material (but are affected by the amount of impurities).

Answer 3

That is called a physical change.