The isotope au-197 is irradiated in a thermal neutron flux of 1018 neutrons/(m²s). the cross section for neutron capture is 99 barn (1 barn= 10-28 m²), and the half- life of the radioactive au-198 produced is 2.7 days. (a) how long does the sample have to be irradiation for 0.1 percent of the target atoms to be destroyed? (b) what is the irradiation time necessary to produce 95% of saturation activity?

they are all solids.

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.