How is carbon 14 dating used

15-Feb-2015 12:28

Carbon-14 has a half-life of 5,730 ± 40 years, meaning that every 5,700 years or so the object loses half its carbon-14.Samples from the past 70,000 years made of wood, charcoal, peat, bone, antler or one of many other carbonates may be dated using this technique.

By examining the object's relation to layers of deposits in the area, and by comparing the object to others found at the site, archaeologists can estimate when the object arrived at the site.

Later called Ötzi the Iceman, small samples from his body were carbon dated by scientists.

Carbon-14, or radiocarbon, is a naturally occurring radioactive isotope that forms when cosmic rays in the upper atmosphere strike nitrogen molecules, which then oxidize to become carbon dioxide.

Green plants absorb the carbon dioxide, so the population of carbon-14 molecules is continually replenished until the plant dies.

Materials that originally came from living things, such as wood and natural fibres, can be dated by measuring the amount of carbon-14 they contain.For example, in 1991, two hikers discovered a mummified man, preserved for centuries in the ice on an alpine mountain.