Question #db7d8

1 Answer
Apr 30, 2017

The amount left is #=22.5g#

Explanation:

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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#