[1] Simply speaking, chemical properties cannot be determined just by viewing or touching the substance; the substance's internal structure must be affected greatly for its chemical properties to be investigated.
When a substance goes under a chemical reaction, the properties will change drastically, resulting in chemical change.
However, for many properties within the scope of physical chemistry, and other disciplines at the boundary between chemistry and physics, the distinction may be a matter of researcher's perspective.
Material properties, both physical and chemical, can be viewed as supervenient; i.e., secondary to the underlying reality.
Materials science will normally consider the chemical properties of a substance to guide its applications.