Question

a radioisotope, Iodine-131, has a half life of 8.1 days. explain what this means. draw a particle diagram for a sample 12 particles of I-131 initially after 8.1 days and after16.2 days.

Answer 1

half-life, means statistically, the random events of disintegration half will have occurred on the average in that time. Half life only works when there are many, many particles: when 12 are involved, one cannot predict when six will have disintegrated. The model fails on small numbers, disintegration is a random event.