Question on: SS1 Physics - Atomic Structure and Radioactivity

Half-life is the time it takes for half of the radioactive nuclei in a sample to undergo decay. It is a characteristic property of each radioactive isotope. By measuring the amount of radioactive isotope remaining in a sample and knowing its half-life, we can determine the age of objects. The age is calculated by comparing the ratio of the remaining radioactive isotope to the original amount present in the sample. The more half-lives that have passed, the smaller the ratio, indicating an older age.