Radiometric dating explained for kids
Tree rings can be counted and their radiocarbon content measured.
Radiocarbon dates are presented in two ways because of this complication.
Radiocarbon dating involves determining the age of an ancient fossil or specimen by measuring its carbon-14 content.
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.
Carbon-14 is also passed onto the animals that eat those plants.