Question

Question #e7721

Answer 1

It ionizes the air molecules.

Explanation:

In a smoke detector, the alpha particle emitter is `Am^241`, and the alpha particles that it emits ionizes the air molecules, forming ions and electrons, which are attracted to a pair of charged plates. When the ions and electrons hit the plates, they provide a small amount of electric current, which stays constant and is monitored by the smoke alarm.

If the smoke enters the detector, then the current drops in the smoke detector, the number of ions and electrons hitting the plates decreases, and the alarm is triggered.