Type radiation used carbon dating
When atoms decay, they emit three types of radiation, alpha, beta and gamma.
A particle of beta radiation can cause spontaneous mutation and cancer when it comes into contact with DNA.
All living cells take up carbon-14, whether from photosynthesis or eating other living cells.
When a living cell dies, it stops taking in carbon-14, because it stops photosynthesising or eating, and then gradually over time the carbon-14 decays and is no longer found in the tissue. The half-life of carbon-14 (the time in which it takes from the radiation emitted from the source to be halved) works out to be 5,730 years.
Though the least powerful of the three types of radiation, alpha particles are nonetheless the most densely ionizing of the three.
That means when alpha rays can cause mutations in any living tissue they come into contact with, potentially causing unusual chemical reactions in the cell and possible cancer.