[填空题]
The half-life, T, in years, of a radioactifq+x6xt 2gcjk1 fi7 2xve 4ygn;xwkvo:8o29ygvisotope can be modelled by the function o:4v8gx2 ygvoyw;9kn $\frac{\ln{0.5}}{\ln{1-\frac{k}{100}}}$ , 0where k is the decay rate, in percent, per year of the isotope.
1.The decay rate of Hydrogen-3 is 5.5 % per year. Find its half-life.
T(5.5)≈ years
The half-life of Uranium-232 (U-232) is 68.9 years. A sample containing 250 grams of U-232 is obtained and stored as a side product of a nuclear fuel cycle.
2.Find the decay rate per year of U-232.
Solving the equation T(k)=68.9 for k, we obtain k= %
3.Find the amount of U-232 left in the sample after:
(3.1) 68.9 years;
grams
(3.2) 100 years.
$u_{101}$≈ grams
