Here's why:
* Elements are pure substances that cannot be broken down into simpler substances by chemical means. Hydrogen (H) and oxygen (O) are examples of elements.
* Changes of state refer to the physical transformations of a substance, like melting, freezing, boiling, or condensing. These changes affect the arrangement and movement of molecules within a substance but don't alter the substance's chemical composition.
Example: Water (H₂O) is a compound made of hydrogen and oxygen. Water can exist in three states: solid (ice), liquid (water), and gas (steam). These are changes of state, but water remains chemically the same (H₂O) throughout.
In summary: Hydrogen and oxygen are elements, not states of matter. While they can combine to form water, which can then undergo changes of state, hydrogen and oxygen themselves are not states of matter.
