Here's why:

* It's a chemical compound: Carbonated water is simply water (H₂O) that has been infused with carbon dioxide (CO₂).

* No biological origin: The water and carbon dioxide come from natural sources, but the process of making carbonated water is purely chemical.

Think of it this way: You can't categorize a rock as a plant or animal because it's not a living organism. Carbonated water is similar; it's a product of chemical reactions, not biological processes.