Can someone help me with this? Iridium-192 is one radioisotope used in brachythe
ID: 859637 • Letter: C
Question
Can someone help me with this? Iridium-192 is one radioisotope used in brachytherapy, In which a radioactive source is placed Inside a patients body to treat cancer. Brachytherapy allows the use of a higher than normal dose to be placed n the tumor while lowering the risk of damage to healthy tissue. Iridium-192 is often used in the head or breast. Answer the following three questions (a, b, and c) based on the radioactive decay curve of iridium-192, shown below. Click on the graph and anus the mouse over a pant to get values for that point. Sample remaining (%) If the initial sample is 2.75 g, what mass of the original iridium- 192 remains after 150 days a) If the initial sample is 2.75 g, what mass of the original iridium-192 remains after 150 days? b) Estimate the half-life of the radioisotope. Number days C) HOW many days would it take for three-fourths of the sample to decay?Explanation / Answer
from the graph t1/2 = 75 days
K1 = 0.693/t1/2
K1 = 0.693/75
K1 = 9.24*10^-3 day^-1
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K1 = 2.303/t log(initial/final)
9.24*10^-3 = 2.303/150 log(2.75/final)
final = 0.6878 gm.
% of remaining = (0.6878/2.75)*100 = 25%
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9.24*10^-3 = 2.303/t log[1/(1-3/4)]
time = 150 days