Here's why:

* Organic chemistry is the study of compounds containing carbon, and the vast majority of organic compounds contain carbon as the central atom.

* Carbon's unique bonding properties allow it to form long chains and complex structures, making it the backbone of a vast array of organic molecules.

* Other elements commonly found in organic compounds, like hydrogen, oxygen, nitrogen, and halogens, are often bonded to carbon atoms.

While there are a few exceptions (like carbon dioxide and carbonates), the presence of carbon is a strong indicator that a compound is organic.