Why is it preferable to use Am in smoke detector? Low stable and highly reactive
High stability over long time and source need not be replaced
High penetration and high ionization
A good source of beta radiation and has a half-life of 432 years

Ionization smoke detectors use americium as a source of alpha particles. Alpha particles from the americium source ionize air molecules. This makes some particles positively charged and some negatively charged. ... Because of this shielding, the smoke detector poses no radiation health risk when they are properly handled.

Explanation:

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