How can physical and chemical properties be used to identify substances?

Physical and chemical properties are fundamental in identifying substances because they provide measurable, unique characteristics. For example, density, melting point, solubility, and reactivity can distinguish one compound from another. Scientists often rely on these tests in labs to confirm composition and purity. In fact, research from Stanford Advanced Materials shows how specific properties are used to differentiate advanced compounds, especially in specialized industries where precision is essential.

Basically, it’s the same way that you identify your friends. If you know that a friend of yours has certain physical properties (height, color of hair and eyes, face, etc), you can identify them using those properties. In chemistry we use the same approach. We measure the physical properties of a substance (like its density, or its color, or its melting point) and look the values up in books. We can measure the chemical properties (what it reacts with) and look those up in books also.