Applications

Radioisotopes have many useful applications in household devices, industry, medicine, and more. The type of radiation emitted and the half-life of the isotope are key factors in determining its suitability for each application. Here are some examples:

(a) Household Fire (Smoke) Alarms:

• Americium-241 is commonly used in smoke alarms.

• It emits alpha particles, which are not harmful when sealed inside the alarm.

• The half-life of americium-241 is long, which ensures the alarm remains effective for many years.

(b) Irradiating Food to Kill Bacteria:

• Gamma radiation is used to kill bacteria and extend the shelf life of food.

• The isotopes used for food irradiation have a suitable half-life that allows them to emit gamma radiation for a sufficient duration without needing frequent replacement.

(c) Sterilisation of Equipment Using Gamma Rays:

• Medical equipment can be sterilised using gamma rays to kill bacteria and other pathogens.

• Isotopes like Cobalt-60 are used because they emit strong gamma radiation and have an appropriate half-life, making them suitable for continuous use.

(d) Measuring and Controlling Thicknesses of Materials:

• In industry, radioactive isotopes are used to measure and control the thickness of materials like paper or metal.

• The choice of isotope depends on the type of material and the penetration ability of the radiation required.

• Beta radiation is often used because it can pass through thin materials and provide a reliable measure of thickness.

(e) Diagnosis and Treatment of Cancer Using Gamma Rays:

• Gamma rays are used in the diagnosis and treatment of cancer because of their ability to penetrate deeply into the body.

• Cobalt-60 is often used in radiotherapy to target and destroy cancer cells. Its half-life is suitable for continuous use over time without the need for frequent replacement.