Radioactive decay
The key idea
Radioactive decay is a spontaneous nuclear transformation. For a large population of identical unstable nuclei, the number remaining follows an exponential law.
Why it matters
The decay of an individual nucleus is unpredictable, yet a large population obeys a remarkably precise statistical law.
A picture to remember
The decay of an individual nucleus is unpredictable, yet a large population obeys a remarkably precise statistical law.