Difference between revisions of "Solutions 3"
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All <sup>99m</sup>Tc has disintegrated and turned into <sup>99</sup>Tc. The number of <sup>99</sup>Tc atoms will therfore be the same as the original number of <sup>99m</sup>Tc atoms. | All <sup>99m</sup>Tc has disintegrated and turned into <sup>99</sup>Tc. The number of <sup>99</sup>Tc atoms will therfore be the same as the original number of <sup>99m</sup>Tc atoms. | ||
| − | N = | + | <math>N=\frac{D}{\lambda}=\frac{4\cdot 10^{7}}{3.21\cdot 10^{-5}}</math> |
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Revision as of 10:47, 19 June 2012
Amount of radioactive material (number of nuclei <-> number of moles <-> weigth) and law of radioactive decay
1:
- 3.2 • 108 Bq
- 383 Bq
- 2.3 • 109 Bq
- 8 • 104 Bq
2:
- 1.78 • 1013 atoms.
- 2 • 1011 atoms.
3: 2.40 g 60Co.
4:
- 2.53 • 105 Bq.
- 7.19 years = 7 years and 68 days.
5: The mass of 99mTc is 20.5 ng. After one week 28 half-times will have past, and the activity will be the following:
D = D0 • (½)28 = 4 • 107 Bq • (½)28 = 0.15 Bq.
All 99mTc has disintegrated and turned into 99Tc. The number of 99Tc atoms will therfore be the same as the original number of 99mTc atoms.
