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Answer 1 · 2017-04-30T18:21:42

The amount left is $=22.5g$

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In the first $8h$ , $50%$ is left, that is $360/2=180g$

In $16h$ , $25%$ is left, that is $360/4=90g$

In $24h$ , $12.5%$ is left, that is $360/8=45g$

In $32h$ , $6.25%$ is left, that is $360/16=22.5g$

The radioactive decay is an exponential function.

$m=m_0*e^(-lambda t)$

Where $lambda$ is the radioactive decay constant

$lambda =ln2/t_(1/2)$

Here, we have

$lambda=ln2/8h^-1$

So,

$m=360*e^(-ln2/8*32)$

$=360*0.0625$

$=22.5g$