Physical Properties:
* Definition: Characteristics that can be observed or measured without changing the substance's chemical composition.
* Examples:
* Color: The way a substance appears to the eye (e.g., blue, red, colorless).
* Density: The mass of a substance per unit volume (e.g., water has a density of 1 g/mL).
* Melting point: The temperature at which a solid changes to a liquid.
* Boiling point: The temperature at which a liquid changes to a gas.
* Solubility: The ability of a substance to dissolve in another (e.g., sugar is soluble in water).
* Hardness: The resistance of a solid to scratching or indentation.
* Odor: The smell of a substance.
* Key Point: Changes in physical properties are usually reversible (e.g., ice melting and then freezing back into ice).
Chemical Properties:
* Definition: Characteristics that describe how a substance reacts with other substances or changes its chemical composition.
* Examples:
* Flammability: The ability of a substance to burn in the presence of oxygen (e.g., wood is flammable).
* Reactivity: The tendency of a substance to undergo chemical reactions (e.g., sodium reacts violently with water).
* Oxidation: The process of a substance combining with oxygen (e.g., rusting of iron).
* Acidity/Basicity: The tendency of a substance to donate or accept hydrogen ions (e.g., lemon juice is acidic, baking soda is basic).
* Decomposition: The breakdown of a substance into simpler substances (e.g., decomposing of food).
* Key Point: Changes in chemical properties are usually irreversible (e.g., burning wood produces ash and gases).
In summary:
* Physical properties describe the outward appearance and behavior of a substance without altering its chemical makeup.
* Chemical properties describe how a substance interacts with other substances and undergoes chemical transformations, changing its composition.
