Question

Question 17 of 20 > Iridium-192 is one radioisotope used in brachytherapy, in which a radioactive source is placed inside a patient's body to treat cancer. Brachytherapy allows the use of a higher than normal dose to be placed near the tumor while lowering the risk of damage to healthy tissue. Iridium-192 is often used in the head or breast. Use the radioactive decay curve of iridium-192 to answer the three questions. 100 90 80 70 60 . . Sample remaining 50 40 30 - . 20

Answer 1

* Initial sample mass 6.25g. From the given graph, 46 % of loot of Iridium 192 Iridium-192 remains In the . After so days 46% of 6.25 g remains 46x625 Joo 25g 2.815 - remains after sodays a From the graph, * Half life the radioisotope From the graph, we can identify half life. Half life is the time required for quanlity to reduce to half of its initial valice 50% of initial amount is reducing a days. " Half life of Iridium 192 = 74 days Time for the sample to decay to Ithy of initial Yetto initial valve 25-14 From graph, 25th of the initial amount reduced to in Time - 150 days valece iso days. Is