1. m. chemical element of no. atóm. 6. Is extremely abundant in nature, both in living beings the mineral world and in the atmosphere. It occurs in several allotropic forms, such as diamond, graphite and charcoal. It forms the basis of organic chemistry, and in addition to its biological importance, has variety of uses and applications in its various forms. One of the isotopes carbon 14 is radioactive and is used for dating artifacts and remains of old, and as a tracer in biological research. (Símb.) C).