Final answer:
Americium-241 is ideal for smoke detectors because it emits alpha particles that ionize the air and create an electric current. When smoke enters the detector, it reduces the flow of ions and triggers an alarm.
Step-by-step explanation:
Americium-241 is an ideal isotope to use in a smoke detector because it emits alpha particles, which ionize the air in the detector. These ionized particles create a small electric current between two electrode plates in the ionizing chamber. When smoke enters the chamber, it impedes the movement of ions and reduces the conductivity of the air, causing a drop in current and triggering an alarm.
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