Answer: 1
Explanation: This is true.
For 60.0 g sample, if it remains 60-52.5=7.5 g, it will go through 60->30->15->7.5, 3 half-life. So the time being taken is 269*3=807 years.
The answer is A it depends on the distance

☃️ Chemical formulae ➝ 
How to find?
For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.

Solution:
❍ Molecular weight of 
= 2 × 126.90
= 253.80
= 254 (approx.)
❍ Given weight: 12.7
Then, no. of moles,
⇛ No. of moles = 12.7 / 254
⇛ No. of moles = 0.05 moles
⚘ No. of moles of Iodine molecule in the given weight = <u>0.05</u><u> </u><u>moles </u>
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