Which among the following is/are pure beta emitter(s) :
**Core Concept**
The question is testing the student's knowledge of the properties of radioactive isotopes used in nuclear medicine, specifically their mode of radiation emission. Beta particles are high-energy electrons emitted by certain radioactive isotopes, which can be either positively charged (beta plus, β+) or negatively charged (beta minus, β-).
**Why the Correct Answer is Right**
A pure beta emitter is an isotope that emits beta particles but does not emit gamma radiation. Phosphorus-32 (32P) is a classic example of a pure beta emitter, emitting beta minus particles (β-) with a relatively short half-life of 14.29 days. This property makes 32P useful for in vivo labeling of cells, proteins, and other molecules in research and clinical settings.
**Why Each Wrong Option is Incorrect**
* **Option A:** Technetium-99m (99mTc) is a metastable nuclear isomer that decays by emitting gamma radiation, making it a pure gamma emitter, not a pure beta emitter.
* **Option B:** Iodine-123 (123I) is a pure gamma emitter, used extensively in nuclear medicine for imaging applications, but it does not emit beta particles.
* **Option D:** This option is blank, so we cannot evaluate it.
**Clinical Pearl / High-Yield Fact**
When working with radioactive isotopes, it's essential to consider their mode of radiation emission to ensure proper handling, storage, and disposal to minimize radiation exposure and prevent contamination.
**Correct Answer:** C.