A knowledge of properties of matter is important not only to scientists but engineers as well (and anybody who is working with matter). The properties on interest, typically, include melting point, boiling point, density, mass, volume, shape, electrical conductivity, heat conductivity, reactivity with other substances (including water, acids, bases, etc.). All applications of matter are dependent on their properties. Here are a few examples:
- Storage and handling of matter requires a knowledge of its properties. Some materials can be stored at room temperature, while cannot be.
- Cleanup and disposal of any accidental spill also requires a knowledge of its properties, such as reactivity (esp. with water)
- Any laboratory experimentation with the matter requires a knowledge of chemical reactivity and physical properties.
- Knowledge of properties like malleability and ductility are needed when trying to make something out of a particular material. For example, gold can be used to make jewelry, copper can be used for making wires, etc.
Hope this helps.