If 12.5 grams of the original sample of cesium-137 remained after 90.6 years, what was the mass of the original sample?

Mass of original sample = 100 g

Explanation:

Half life of cesium-137 = 30.17 years

Where, k is rate constant

So,  

The rate constant, k = 0.02297 year⁻¹

Time = 90.6 years

Using integrated rate law for first order kinetics as:

Where,  

is the concentration at time t

is the initial concentration

Initial concentration = ?

Final concentration = 12.5 grams

Applying in the above equation, we get that:-

Mass of original sample = 100 g

a:

by the combination of an unlimited number of elements

explanation:

two years ago, when picking flowers in the mountains back of yosemite valley, i found a book. it was blotted and storm-beaten; all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however; many of the inner pages were well preserved. and although all were more or less stained and torn, whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today; its granite pages have been torn and blurred by the same storms that wasted the castaway book.

two years ago, when picking flowers in the mountains back of yosemite valley; i found a book. it was blotted and storm-beaten, all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however, many of the inner pages were well preserved. and although all were more or less stained and torn; whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today, its granite pages have been torn and blurred by the same storms that wasted the castaway book.