Final answer:
The two primary types of smoke detectors are ionization, which uses radioactive americium to detect smoke, and photoelectric, which utilizes a light source. Ionization smoke detectors trigger an alarm by detecting changes in electrical current caused by smoke disrupting ionized air. These devices showcase the practical use of nuclear chemistry for safety purposes.
Step-by-step explanation:
The two main types of smoke detectors are ionization smoke detectors and photoelectric smoke detectors. Ionization smoke detectors contain a small amount of radioactive material, americium-241, which emits alpha particles that ionize the air. This action creates a small electric current between two metal plates in the detector. When smoke from a fire enters the ionization chamber, it disrupts the flow of ions and reduces the current; if the current drops below a certain threshold, the alarm is triggered.
A typical smoke detector has an electric circuit with two metal plates and a battery that provides voltage between the plates. Regular battery replacement is necessary due to the constant current flow between the plates. Smoke detectors are a vital application of nuclear chemistry in everyday safety and security, using the principles of radiation detection to safeguard lives.