Question 1 aj Define the term "radioisotope". b) Define the term "radiopharmaceutical". [1.1] Question 2 aj Meta-Technetium-99 is a radioisotope commonly used in radiopharmaceutical applications. It is obtained from the decay of Molybdenum-99, which is itself produced artificially either by neutron bombardment of a target material or chemically separated from the products of uranium-235 fission. Describe the process by which meta- Technetium-99 may be isolated ready for incorporation into a radiopharmaceutical, starting with the two methods for obtaining Molybednum-99. b) Fluorine-18 is a radioisotope commonly used in positron emission tomography (PET scans). Describe the process by which Fluorine-18 may be isolated ready for incorporation into a radiopharmaceutical. [Suggested word count 200] [1.2] Question 3 Describe the key properties required of radioisotopes used for ( medical imaging (gamma camera, PET scans] lij brachytherapy (e g. radioactive implants) ill) internal 'systemic' radiotherapy (e.g. iodine-131 thyroid cancer treatment) [Suggested word count 200] [1.3]