Problema Solution

The half-life of a radioactive kind of indium is 3 days. How much will be left after 6 days, if you start with 88 grams of it?

Answer provided by our tutors

The formula for determining the amount of substance left is:

A=Ce^(kt), where C is the initial amount, k is the decay constant, and t is time.

Given the half-life of t=3 days we have:

C/2=Ce^(3k)

½=e^(3k)

Taking log both sides:

Ln(1/2)=ln(e^(3k)

-0.693=3k

k=-0.693/3

k=-0.231049

Amount after t = 6 days and C = 88 grams initial amount:

A=88*e^((-0.693/3)*6)

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click here to see the calculation for A

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A= 22 grams

After 6 days there will be 22 grams of indium left.