Half-Life of Cobalt-60
**Core Concept**
The half-life of a radioactive substance is the time required for its radioactivity to decrease by half due to nuclear decay. Cobalt-60 is a radioactive isotope used in medicine for radiation therapy and industrial applications.
**Why the Correct Answer is Right**
Cobalt-60 has a half-life of approximately 5.2713 years. This means that every 5.2713 years, the radioactivity of Cobalt-60 decreases by half. This property makes it a useful isotope for applications where controlled radiation exposure is required. The half-life of Cobalt-60 is a critical factor in its handling, storage, and usage.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because the half-life of Cobalt-60 is not 1 year.
**Option B:** Incorrect because the half-life of Cobalt-60 is not 10 years.
**Option C:** Incorrect because the half-life of Cobalt-60 is not 20 years.
**Clinical Pearl / High-Yield Fact**
The half-life of a radioactive substance is a key factor in determining its potential for radiation exposure and its suitability for medical or industrial applications. Understanding the half-life of Cobalt-60 is essential for healthcare professionals handling this isotope.
**Correct Answer:** A. 5.2713 years