- Created by: Abbie
- Created on: 26-02-12 12:50
Each time an unstable nucleus decays and emits radiation that means there's one more radioactive nucleus that isn't there to decay later.
As more unstable nuclei decay, the radioactivity of the source as a whole decreases - the older a radioactive source is the less radiation it emits.
The problem with trying to measure how long it takes for nearly all the nuclei to decay is that the activity never reaches zero. This is why we use half-life…