* Definition of a compound: A compound is formed when two or more different elements chemically combine in a fixed ratio.
* Definition of an element: An element is a pure substance that cannot be broken down further by chemical means. It consists of only one type of atom.
Chemical changes rearrange atoms, but don't create or destroy them. Therefore, a chemical change can break down a compound into its constituent elements, but it cannot create new elements.
Example: Water (H₂O) is a compound made of hydrogen (H) and oxygen (O). Electrolysis (a chemical change) can break down water into hydrogen gas and oxygen gas, but it doesn't create new elements.
Key Takeaway: While chemical reactions can break down compounds, they cannot create new elements. The elements present in a compound will always be the same, even after a chemical change.
