The half-life of a short-lived radionuclide can be determined by measuring the amount of radioactivity remaining after a certain amount of time has passed. For example, if a sample of a radionuclide with a microsecond half-life is measured after one second, the amount of radioactivity remaining should be half of the original amount. Similarly, if a sample of a radionuclide with a nanosecond half-life is measured after one second, the amount of radioactivity remaining should be one millionth of the original amount.