Flammability is not a physical property; it is a chemical property. A physical property is a characteristic of matter that does not involve changes in its chemical composition. Examples of physical properties include color, density, melting point, and boiling point. These properties describe how a substance behaves without altering its chemical structure.
In contrast, flammability is a chemical property because it relates to how a substance undergoes a chemical change when it burns or combusts. When a material burns, it reacts with oxygen, and its chemical composition changes as it transforms into different chemical compounds. This chemical change is what distinguishes flammability as a chemical property.