Answer:
Reactivity of the copper strip
Step-by-step explanation:
The matter properties can be classified as chemical property or physical property. The first refers to the properties that, when analyzed, change the composition of the matter, it means that a chemical property is a capacity of a substance to transform in other, such as the combustibility (the property to react with a comburent to form carbonic gas), the oxidation, and in general the reactivity.
The physical properties are the ones that are possible to be analyzed without changing the composition of a substance, such as the color, the density, the odor, and the pH.
So, the density of the copper strip, odor of the chlorine solution, and color of the chlorine solution are physical properties, and the reactivity of the copper strip is a chemical property.