Which of the following are physical properties?

Rusting

Flammability

Mass

Density

- Rusting and flammability are chemical properties, while mass and density are physical properties.

Physical properties are characteristics of a substance that can be observed or measured without changing its chemical composition. Among the given options, the physical properties are:

- Mass: Mass is a measure of the amount of matter in an object. It is a physical property because it can be measured without changing the substance's chemical composition.

- Density: Density is the measure of how much mass is contained in a given volume. It is a physical property because it can be determined by dividing the mass of an object by its volume.

On the other hand:

- Rusting: Rusting is a chemical reaction that occurs when iron or steel reacts with oxygen in the presence of moisture. It is not a physical property but rather a chemical change.

- Flammability: Flammability is the ability of a substance to ignite or burn. It is also a chemical property, not a physical property, as it reflects the substance's ability to undergo a chemical reaction with oxygen.