Which of the following statements about the use of radioisotopes is not correct? They are used to

Analyze the question: We need the one statement that is NOT a correct use of radioisotopes.

Concept: Radioisotopes (radioactive isotopes) are used in:

• Agriculture/biology: Radiation induces mutations in crops and animals, producing improved varieties.
• Tracers: Radioactive tracers (e.g. carbon-14, phosphorus-32) track metabolic pathways, such as photosynthesis or nutrient uptake in plants and animals.
• Dating: Long-lived isotopes like uranium-238 (to lead-206) are used to estimate the age of rocks, and carbon-14 is used for dating once-living materials.
• Medicine: Treating cancer (cobalt-60), sterilising equipment, and tracing thyroid function (iodine-131).

Step-by-step check:

• A. Induce mutations – Correct. Gamma radiation is used to produce new plant varieties.
• B. Trace metabolic paths – Correct. This is the classic tracer application.
• C. Estimate the age of rocks – Correct. Radioactive dating with uranium-lead or potassium-argon methods.
• D. Locate broken bones – Not correct. Broken bones are located using X-rays, which are electromagnetic radiation produced by an X-ray machine, not a radioisotope. (Radioisotopes are used in bone scans to detect some diseases, but locating fractures is the job of X-ray imaging.)

Tip: In "which is NOT correct" questions, test each option and eliminate the true ones. Remember: broken bones → X-rays; rock age → radioisotope dating; metabolic paths → tracers; new varieties → mutation by radiation.