Question: do electrons take part in a chain reaction of a radio active element such as americium-241 found in smoke detectors

Timothy Chege answered on 30 May 2018:

To oversimplify this. Think of Americium-241 as constantly decaying(half life; 432 years) and releases weak gamma rays. This ionizing radiation is utilized to create a steady electric current flow and when smoke enters the smoke detector’s chamber that has Americium-241 it creates a disturbance and the alarm is triggered. This said, the use of such smoke detectors is a health risk as prolonged exposure to a radioactive material is detrimental to your health.