Answer:
the error could have been the fact that the unit for volume wasn't changed from cm³ to dm³
hence the calculation error
the solution to this would be first dividing the volume by 1000 to get that same amount in dm³ which is the standard unit to be used for volume-density calculations
That would be A.
2.5*2*10^(10-7)=5*10^3
Bbgfbsthgbdvdge fr that’s crazy d. Thx
<span>number of moles are the amount of substance of an element .
number of moles can be calculated as follows;
number of moles = mass present / molar mass of element
molar mass of Ar - 40 g/mol
number of moles of Ar = 22 g / 40 g/mol = 0.55 mol .
there are 0.55 mol of Ar</span>
Ln(800/3200) = - kt
t = 24 years.
ln(0.25) = -k*24
(- 1.3863) = -k*24
1.3863 / 24 = k
0.05776 = k
ln(0.5) = -k*t
-0.6931 = - 0.05776 t
12 = t
I don't know if you can just look at the question and know the answer. If 24 years is a quarter life then is it obvious that the 1/2 life is 12 years? It might be, but the method I've used works for sure.
