* Chemical Change: This is when a substance undergoes a transformation that alters its chemical composition. New substances are formed, with different properties.

* Physical Property: This describes a characteristic of a substance that can be observed or measured without changing its chemical makeup.

Let's break it down with some examples:

Chemical Changes:

* Burning wood: Wood (cellulose) reacts with oxygen to form ash, carbon dioxide, and water. The chemical composition of the wood has changed, creating new substances.

* Rusting iron: Iron reacts with oxygen and water to form iron oxide (rust). This is a new compound with different properties than iron.

* Baking a cake: The ingredients (flour, sugar, eggs, etc.) undergo chemical reactions when heated, forming a new substance with a different texture and taste.

Physical Properties:

* Color: The color of a substance is a physical property.

* Density: How much mass is packed into a given volume is a physical property.

* Melting Point: The temperature at which a solid turns into a liquid is a physical property.

* Boiling Point: The temperature at which a liquid turns into a gas is a physical property.

* Conductivity: How well a substance conducts heat or electricity is a physical property.

Key Differences:

* Chemical Changes: Create new substances with different chemical compositions. They are often irreversible.

* Physical Properties: Can be observed or measured without changing the substance's chemical makeup. They are typically reversible.

Let me know if you'd like more examples or explanations!