Definition of carbon-14 in US English:



  • A long-lived naturally occurring radioactive carbon isotope of mass 14, used in carbon dating and as a tracer in biochemistry.

    • ‘When the organism dies, it stops taking in any new carbon, and the amount of carbon-14 inside it gradually decreases as it decays.’
    • ‘After the organism dies and becomes a fossil, carbon-14 continues to decay without being replaced. To measure the amount of radiocarbon left in a fossil.’
    • ‘Carbon-14 atoms are created when cosmic rays from the sun collide with atoms in the atmosphere. Learn about carbon-14 atoms and carbon-14 atom creation.’