- Characteristic of the substance: The property should be something that is unique to the substance and can be used to distinguish it from other substances.
- Easily observed or measured: The property should be something that can be easily seen, felt, or measured, so that it can be used for identification purposes.
- Consistent and reliable: The property should be something that is consistent and reliable, so that it can be used to identify a substance even under different conditions.
Some common properties that are used to identify substances include:
- Physical properties: These properties include things like a substance's color, shape, density, melting point, and boiling point.
- Chemical properties: These properties include things like a substance's reactivity with other substances, its flammability, and its solubility.
- Spectroscopic properties: These properties include things like a substance's absorption spectrum, emission spectrum, and mass spectrum.
The specific properties that are used to identify a substance will depend on the nature of the substance and the purpose of the identification. For example, if you are trying to identify a metal, you might use its density and melting point. If you are trying to identify a gas, you might use its flammability and its solubility.