Here's why:

* Compound: A substance formed when two or more different elements are chemically bonded together in a fixed ratio.

* Mixture: A combination of two or more substances where each substance retains its own properties and can be separated by physical means.

Sucrose (table sugar) is made up of carbon, hydrogen, and oxygen atoms bonded together in a specific arrangement. This chemical bonding creates a new substance with properties distinct from its individual components.

You can't separate sucrose into its constituent elements (carbon, hydrogen, oxygen) by simple physical methods like filtration or evaporation. You would need a chemical reaction to break down the compound.