Americium-241 is a radioactive isotope that emits alpha particles. How americium-241 is used in smoke alarms ?

Americium-241 is used in smoke detectors due to its radioactive properties. Here's how it works:

1. A small amount of americium-241 is placed in an ionization chamber, a space within the smoke detector. This chamber is connected to a battery and a small current is flowing through it.

2. The americium-241 emits alpha particles. These particles ionize the air in the chamber, which means they knock electrons off the air molecules, creating ions.

3. These ions carry a charge and due to this charge, they are attracted to the plates in the chamber, allowing the current to flow.

4. When smoke enters the chamber, it disrupts this flow of ions. This causes a drop in the current.

5. The smoke detector senses this drop in current and this triggers the alarm.

So, the americium-241 is a crucial part of the smoke detector's ability to detect smoke.