The branch of science that applies to substances containing carbon is called organic chemistry.

Here's why:

* Carbon's Unique Bonding: Carbon has the remarkable ability to form strong, stable bonds with itself and other elements, creating a vast array of complex molecules. This property forms the basis of life as we know it.

* Diversity of Carbon Compounds: The diversity of carbon compounds is immense, ranging from simple hydrocarbons to complex biomolecules like proteins, carbohydrates, and nucleic acids.

* Focus of Organic Chemistry: Organic chemistry specifically focuses on the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds.

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