232,606 views
15 votes
15 votes
The half-life of silicon-32 is 710 years. If 100 grams is present now,how much will be present in 300 years? (Round k-value to six decimalplaces and round your final answer to one decimal place) y= nekkt

User GHZ
by
2.8k points

1 Answer

22 votes
22 votes

We will have the following:


N=Noe^(kt)
50=100e^(710k)\Rightarrow0.5=e^(710k)\Rightarrow\ln (0.5)=710k\Rightarrow k=(\ln(0.5))/(710)

From this we have that the equation is:


N=100e^{((\ln(0.5))/(710))t}

Now, we replace the time:


N=100e^{((\ln(0.5)/(710))(300)}\Rightarrow N\approx74.6

So, there will be approximately 74.6 grams of silicon-32.

User Vincent Labatut
by
3.3k points