The 'half-life' of a pure sample of some radioactive element is: Question 32 options: the time it takes for the mass of the material to be cut in half as the atoms decay, shedding part of their mass the time it take for the mass of the material to be increased by 50% as the new 'daughter' products accumulate the time it takes for half of the original atoms in the material to be converted to the stable daughter product exactly half of the time it would take for the entire sample to decay away completely to the stable form