[填空题]
The half-life, T, in years, of a radiocglojnp 8 a24 -i q..1lhpn4wuactive isotope can be modelled by the 3z,xnhnzctu.:9g bda9r8 8gxfunctch88 .argbz znt:9 nxxd ,u93gion
$\frac{\ln{0.5}}{\ln{1-\frac{k}{100}}}$ , 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
