Answer :
Final answer:
Americium-241 is the element used in smoke detectors, serving as an α-decay emitter to ionize air and detect smoke. A typical smoke detector contains around 0.25 mg of Americium-241. Thus, the correct option is d) Americium.
Explanation:
The element used in smoke detectors is americium (f) Americium-241. This isotope is an α-decay emitter and is essential for the function of smoke detectors commonly used in homes and buildings. Americium-241 ionizes the air between two electrode plates within the ionization chamber of the detector. This ionization supports a small but steady electric current. When smoke enters the chamber, it interrupts the ion flow, reducing the air's conductivity and causing the current to drop sharply. This change triggers the alarm, alerting occupants to the presence of smoke and potential fire.
A typical smoke detector contains a minuscule amount of about 0.25 mg of Americium-241 embedded within its structure. Given that 1 g of Americium-241 has an activity of 1.26 × 10¹¹ Bq, the activity of 0.25 mg within the smoke detector would be calculated by proportionally reducing the activity based on the mass present.
