Half life of cobalt-60 is –
**Core Concept**
Cobalt-60 is a radioactive isotope used in medicine for radiation therapy and diagnostic imaging. Its half-life is a crucial parameter in radiation safety and dosimetry.
**Why the Correct Answer is Right**
The half-life of cobalt-60 is approximately 5.2713 years. This means that every 5.27 years, the radioactivity of cobalt-60 decreases by half. This property makes it suitable for use in radiation therapy, where a consistent dose of radiation is required over time. The half-life of cobalt-60 is a result of the radioactive decay of the isotope, specifically through beta decay, where a neutron in the nucleus is converted into a proton and an electron.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the half-life of cobalt-60 is not 1 year, which would be too short for its use in radiation therapy.
* **Option B:** This option is incorrect because the half-life of cobalt-60 is not 10 years, which would be longer than its actual half-life.
* **Option D:** This option is incorrect because the half-life of cobalt-60 is not 2 years, which would be too short for its use in radiation therapy.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the half-life of radioactive isotopes like cobalt-60 affects their radiation safety and dosimetry. Understanding the half-life is crucial for radiation oncologists and medical physicists to ensure accurate dosing and minimize radiation exposure to patients and staff.
**Correct Answer:** . 5.2713 years