Clinically useful radiation from cobalt 60 is
**Core Concept**
Cobalt-60 is a radioactive isotope of cobalt that emits gamma radiation, making it a useful source for radiation therapy in cancer treatment. The gamma rays have a high energy level, which allows for deep penetration into tissues, making it effective for treating tumors.
**Why the Correct Answer is Right**
The gamma radiation emitted by cobalt-60 is clinically useful because it can penetrate tissues and destroy cancer cells. This is due to the high energy level of the gamma rays, which allows them to travel deep into the body and cause damage to the DNA of cancer cells, ultimately leading to cell death. The gamma radiation is also highly ionizing, which means it can cause damage to the DNA of cancer cells, leading to cell death.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not applicable as it does not mention a specific radiation type. While it's true that gamma radiation is a type of ionizing radiation, this option is too vague to be a correct answer.
**Option B:** This option is incorrect because while beta radiation is also a type of radiation, it has a much shorter range and is less penetrating than gamma radiation, making it less suitable for radiation therapy.
**Option C:** This option is incorrect because while alpha radiation is highly ionizing, it has a very short range and is easily stopped by a sheet of paper, making it unsuitable for radiation therapy.
**Clinical Pearl / High-Yield Fact**
It's worth noting that cobalt-60 has a half-life of approximately 5.27 years, which means that it decays slowly over time, making it a relatively stable source of radiation for clinical use.
**Correct Answer:** C. Gamma radiation.