* Properties of Matter: Properties are the characteristics that describe a substance. They fall into two main categories:
* Physical Properties: These can be observed without changing the substance's chemical composition. Examples include color, density, melting point, boiling point, conductivity, and solubility.
* Chemical Properties: These describe how a substance interacts with other substances or how it changes under specific conditions. Examples include flammability, reactivity with acids, and tendency to oxidize.
* Chemical Changes: These are processes where new substances are formed, breaking and reforming chemical bonds. Examples include burning, rusting, cooking, and digestion.
Key Points:
* Physical properties can be observed in both pure substances and mixtures, whether or not a chemical change is occurring. For instance, you can observe the color of water (a pure substance) or the color of salt water (a mixture) without changing their chemical makeup.
* Chemical properties are often *revealed* during chemical changes because the change itself demonstrates how the substance interacts or transforms. For example, the flammability of wood is observed when it burns, a chemical change that produces ash and smoke.
In summary:
* Physical properties are observable all the time.
* Chemical properties are often revealed during chemical changes, but they exist even when a substance isn't actively reacting.
Let me know if you have any other questions!
