Carbon 13 carbon dating
(kär'bən) Symbol CA naturally abundant, nonmetallic element that occurs in all organic compounds and can be found in all known forms of life.
Diamonds and graphite are pure forms, and carbon is a major constituent of coal, petroleum, and natural gas.
Libby calculated the half-life of carbon-14 as 5568, a figure now known as the Libby half-life.
Following a conference at the University of Cambridge in 1962, a more accurate figure of 5730 years was agreed upon and this figure is now known as the Cambridge half-life.
Atomic number 6; atomic weight 12.011; sublimation point above 3,500°C; boiling point 4,827°C; specific gravity of amorphous carbon 1.8 to 2.1, of diamond 3.15 to 3.53, of graphite 1.9 to 2.3; valence 2, 3, 4.An age could be estimated by measuring the amount of carbon-14 present in the sample and comparing this against an internationally used reference standard.