A medical technician is working with the four samples of radionuclides listed in the table below. Initially, each sample contains 23.00 μmol of the radionuclide. First, order the samples by decreasing initial radioactivity. Then calculate how long it will take for the amount of radionuclide in each sample to decrease to 1/8 of the initial amount. sample A C D symbol 60 27 103 46 55 26 141 radionuclide 58 Co Pd Fe Ce half-life 5.0 years 17. days 3. years 33. days initial radioactivity (choose one) ✓ (choose one) ♥ (choose one) ✓ (choose one) ✓ time for amount of radionuclide to decrease to 1/8 of initial amount years days years days Ś

O Complete the missing nuclear symbol in the equation below. 59 Fe 26 58Fe+ 26

Iridium-192 is one radioisotope used in brachytherapy, in which a radioactive source is placed inside a pati- cancer. Brachytherapy allows the use of a higher than normal dose to be placed near the tumor while lower 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. $ Sample remaining (%) 4 100- R 90- 80- 70- 60- 50- 40- 30- 20- 80 90 100 110 120 130 140 150 160 170 180 190 Time (days) If the initial sample is 5.25 g, what mass of the original iridium-192 remains after 105 days? 10- F ● 0 10 20 30 40 50 60 70 Search or type URL % 5 T MacBook Pro 6 B Y H & 7 U N +00 8 J 1 M K O P

What is needed to balance the nuclear fission reaction below?  n+U→Te+ ? +2n