Naturally occurring graphite occurs in two forms, alpha and beta.These two forms have identical physical properties but different crystal structures.But it is possible to measure the time taken for half of the nuclei in a radioactive material to decay.This is called the half life of radioactive material or radioisotope.Radiocarbon dating can be used on samples of bone, cloth, wood and plant fibers.
The stable form of carbon is carbon 12 and the radioactive isotope carbon 14 decays over time into nitrogen 14 and other particles.
The release of radiation is also a random event and overtime the activity of the radioactive material decreases.
It is not possible to predict when an individual nucleus in a radioactive material will decay.
Half life can be defined as the time taken for the number of nuclei in a radioactive material to halve.
It can also be defined as the time taken for the count rate of a sample of radioactive material to fall to half of its starting level.