Did you detect a difference in the radiation levels between the intact smoke detector and the americium-241 removed from the smoke detector? if so why do you think the smoke detector is designed with that difference?

Question

Rocketfuel

Physics

20 August, 03:32

Did you detect a difference in the radiation levels between the intact smoke detector and the americium-241 removed from the smoke detector? if so why do you think the smoke detector is designed with that difference?

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Answers (1)

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Brock Li · Answer 1

Lab results:

Smoke detector = 40.0 cpm Geiger counter

Americium-241 = 10,400 cpm Geiger counter

The great difference in the radiation level means that Americium-241 is more radioactive than the smoke detector itself. Americium-241 is used as a source of alpha radiation. This radiation ionizes the air particles inside the smoke detector allowing it to conduct small amounts of electric current. For example, if smoke particles go inside the smoke detector, these are hit by alpha radiation and thus causing a drop in current. The drop in current is detected by the smoke detector which then sets off the alarm.