In chemistry, to be classified as an organic substance, a substance must contain what element?

To be classified as an organic substance, the key requirement is the presence of carbon atoms. Organic chemistry primarily studies compounds that consist of carbon, often in combination with other elements such as hydrogen, oxygen, nitrogen, sulfur, and phosphorus. The unique ability of carbon to form stable bonds with many elements, including itself, allows for the vast diversity of organic compounds, which can include anything from simple molecules like methane to complex macromolecules like proteins and DNA.

While oxygen, nitrogen, and hydrogen can be part of organic molecules, their presence alone does not qualify a substance as organic. Carbon is the fundamental building block of organic chemistry, making it the definitive element that categorizes a substance as organic.