* Physical Change: A change in the form or appearance of a substance, but not its chemical composition.
* Chemical Change: A change that results in the formation of new substances with different chemical properties.
When a substance melts, it transitions from a solid to a liquid state. The molecules themselves remain the same; they simply have more freedom to move around.
Here are some examples to illustrate:
* Melting Ice: Ice (H₂O) is the solid form of water. When it melts, it becomes liquid water (H₂O). The chemical formula remains the same.
* Melting Chocolate: Solid chocolate melts into liquid chocolate. The chemical composition of the chocolate doesn't change, just its physical state.
Key Takeaway: Melting is a physical change because it only alters the state of matter, not the chemical makeup of the substance.
