MPO50000: Nine Laws Of Slot Cars

MPO50000 The alpha particles generated by the americium have the following property: They ionize the oxygen and nitrogen atoms of the air in the chamber. Alpha radiation cannot penetrate a sheet of paper, and it is blocked by several centimeters of air. Photoelectric smoke detectors therefore use light in a different way. There would have to be a LOT of smoke before the alarm would go off -- the smoke would have to be thick enough to completely block out the light. When smoke enters, it scatters light onto the sensor, triggering the alarm. The americium in the smoke detector could only pose a danger if you were to inhale it.|Value in a Supercar?