Please finish the third question, answer is 54.6 1. Nuclear Chemistry (20 points
ID: 698088 • Letter: P
Question
Please finish the third question, answer is 54.6 1. Nuclear Chemistry (20 points) CM132F17 Exam 4-Practice Exam Biochemistry, Nuclear, Metal lons) In High Dose Rate Brachytherapy, administer high doses of radiation to tumors over a short time apy, removable radioactive implants or "seeds" are used to period. Iridium-192, with a half- he common radioisotope used in the treatment of prostate and other forms of cancer cays by beta emission. Which of the following would be the product of 1" Ir decay? 192 78 193Os 76 en new, a typical iridium seed has an activity of 0.500 millicuries (mCi). What will the activity of the seed be after 1 year? A) 0.407 mCi B) 0.499 mCi C) 0.0165 mCi D) 1.70 mCi ii. How many nanograms 19?Ir are present in an iridium seed with an activity of 0.500 mCi? The atomic mass of 1921r is 191 96gmol. (1 ng 1×10-9 grams). ShbngExplanation / Answer
1. beta(0e-1) emmission results product having same mass number with reactant,z+1 atomic number.
192-Ir77 ----> 192-Pt76 + beta(0e-1)
2. T1/2 = 74.2 days
k = 0.693/74.2 = 0.00934 day-1
k = (1/t)ln(a/x)
a = initial activity = 0.5 mci
x= activity afetr time,t = ?
0.00934 = (1/(1*365))ln(0.5/x)
x = 0.0165 mci