Match List-I with List-II and select the correct answer using the code given below the Lists: List-I (Element) A. Isotope of Uranium B. Isotope of Cobalt C. Isotope of Iodine D. Isotope of Radium List-II (Application) 1. Treatment of cancer 2. Treatment of goitre 3. Treatment of secondary cancer 4. Nuclear fuel Code: A B C D

The correct matching of isotopes to their applications is as follows: (A) Uranium-235 is primarily used as nuclear fuel for fission in reactors and weapons. (B) Cobalt-60 is a widely used radioisotope for the external beam treatment of cancer due to its high-energy gamma emission. (C) Iodine-131 is specifically absorbed by the thyroid gland and is the standard treatment for goitre (hyperthyroidism) and thyroid cancer [1]. (D) Radium isotopes, such as Radium-223, are used in targeted alpha therapy for the treatment of secondary cancer, particularly bone metastases [1]. Historically, Radium-226 was also used in brachytherapy for various cancers. Therefore, the sequence A-4, B-1, C-2, D-3 corresponds to Option 3.

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > Atomic explosion (Nuclear fatlout): > p. 83