This limit is currently accepted by nearly all radiocarbon dating practitioners.
It follows that the older a date is, even within this 'limit', the greater are the doubts about the date's accuracy.
Usually a proton is knocked out of the nitrogen atom's nucleus and is replaced with the neutron.
The proton takes an electron with it and becomes an atom of hydrogen.
BASIS OF RADIOCARBON DATING Radiocarbon dating compares the amount of normal carbon with the amount of radioactive carbon in a sample.