* Element: An element is a pure substance made up of only one type of atom (like oxygen or carbon). Soda is made of many different substances.

* Compound: A compound is a substance made up of two or more elements chemically bonded together (like water, which is H₂O). Soda has several compounds (sugar, carbon dioxide, etc.) but they aren't chemically bonded in a single, new compound.

* Solution: A solution is a homogeneous mixture where one substance (the solute) is dissolved evenly throughout another substance (the solvent). Soda fits this definition, as the sugar, flavorings, and carbon dioxide are dissolved in the water.

* Heterogeneous mixture: A heterogeneous mixture has components that are not evenly distributed (like sand and water). Soda appears uniform throughout, meaning it's homogeneous.

Key takeaway: Even though soda contains multiple substances, they are evenly distributed and dissolved in the water, making it a homogeneous mixture.