Radiocontrast dyes are considered safe because the isotopes have short half-lives and the isotopes coat the gastrointestinal tract and are not absorbed by normal tissue. If a patient ingests 10.0 mg of iodine, how long until the iodine-134 is 99% out of the patient's system if the half-life of iodine-134 is 52.6 minutes?

Respuesta :

the answer is D.6.14hr.

Answer:

Time till the 99% of the iodine is out of the system is 5.82 hours.

Explanation:

Initial amount of Iodine-134 =[tex]N_o=10.0 mg[/tex]

Final amount of iodine-134 left = N = [tex](100\%-99\%) of 10.0 mg = 1\% of 10 mg=0.1 mg[/tex]

Half life of iodine-134 = [tex]t_{\frac{1}{2}}=52.6 min[/tex]

Time till the 99% of the iodine is out of the system = t

Decay constant =[tex]\lambda [/tex]

[tex]\lambda =\frac{0.693}{t_{\frac{1}{2}}}=\frac{0.693}{52.6 min}=0.0131749 min^{-1}[/tex]

[tex]\log N=\log N_o-\frac{\lambda t}{2.303}[/tex]

[tex]\log\frac{N}{N_o}=\frac{-\lambda t}{2.303}[/tex]

[tex]\log\frac{0.1 mg}{10 mg}=-\frac{0.0131749 min ^{-1}t}{2.303}[/tex]

t = 349.60417 min =5.8267 hours

(1 hour = 60 min)

Time till the 99% of the iodine is out of the system is 5.82 hours.

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