Why is there a radioactive source in a smoke detector?
A)It makes the smoke particles radioactive.
B)It ionizes the air.
C)It powers the alarm when the battery wears out.
D)none of the above

Question

Quizplus · Accepted Answer

The radioactive source (usually Americium-241) in a smoke detector is used to ionize the air within the device. This creates a small electrical current that is disrupted by smoke particles, triggering the alarm. It does not make the smoke particles themselves radioactive, as they don't come into contact with the source. It also does not power the alarm when the battery wears out, as the source itself has a half-life of approximately 432 years and does not need replacing during the lifespan of the detector.

Why Is There a Radioactive Source in a Smoke Detector