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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answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e