Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Components (hierarchy name)
4. components (objects parts)
5. [components by specific context]
6. material components

Anotations

Scope note:

Groups of atoms capable of selective absorption of electromagnetic radiation, usually in the ultraviolet region, resulting in the coloration of organic compounds. The carbonyl and diazo groups are examples of chromophores.