When the organism dies, no more carbon is absorbed; the radiocarbon remaining in the dead organic matter continues to decay. Therefore the more time that has passed since the organism´s death, the less radiocarbon will be present in the remains. This process of disintegration takes place at a constant rate. The rate is expressed as the "half-life" of a radioactive element - that is, the amount necessary for one-half the total amount of the radioactive element present in the sample to disintegrate.