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General Chemistry

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Medical Use of Iodine-124 and Half-Life

CHEM-@VKETP

​Iodine (I-124) has been used as an attractive isotope for medicinal use. $ \text Na_{ }^{ 124 }{ I }$ is potentially useful for diagnosis and dosimetry for thyroid disease using Positron Emission Tomography (PET imaging).

If the patient requires $ \text 6.2 \ g$ of I-124, how much total mass of $ \text Na_{ }^{ 124 }{ I }$ should be purchased from the supplier?

The half-life of iodine-124 is 4.2 days. The delivery time is 7 days from the vendor.

The atomic mass of $NaI$ = 149.89

Use the following formulas to answer the question:

${ t }_{ 1/2 }=\cfrac { ln \ 2 }{ k } =\cfrac { 0.693 }{ k }$

and

$ln\cfrac { A_o }{ A } =kt$

A

$ 18.52 \ g \ Na^{ 124 }{ I }$.

B

$ 21.56 \ g \ Na^{ 124 }{ I }$.

C

$ 19.68 \ g \ Na^{ 124 }{ I }$.

D

$ 23.79 \ g \ Na^{ 124 }{ I }$.