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Physics/Smoke Alarms


Hi, I have recently become concerned about the smoke alarm in my bedroom, as the other day my partner was testing it and lit a match to do so. However, he struck it close to the alarm, meaning the flame from two safety matches was on the alarm, and probably also went into it. This set the smoke alarm off and he quickly blew them out. I have since read that you should not test smoke alarms in this way. I am concerned about the risk of inhalation of americium-241 from doing this, as the smoke alarm is still in the bedroom.
Thank you for your time.

The 241Am is customarily embedded as a coating on steel the way our lab sources are, and not terribly concentrated.  You shouldn't try to burn up the plastic housing on smoke alarms with fire, no, but the alpha emitter should still be quite safely contained.


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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