Chemical properties describe how a substance reacts with other substances. For example, some substances are flammable (they burn easily), while others are not. Some substances are corrosive (they can eat away at other materials), while others are not.

Physical properties describe the physical characteristics of a substance, such as its color, shape, density, and melting point. For example, some substances are solids, while others are liquids or gases. Some substances are hard, while others are soft. Some substances are heavy, while others are light.

Both chemical and physical properties can be used to classify substances. For example, all flammable substances can be grouped together into one class. All corrosive substances can be grouped together into another class. And so on.

By classifying substances by their properties, we can learn more about them and how they interact with each other. This information can be used to make informed decisions about how to use and store different substances.