The maximum permissible workday dose for occupational exposure to radiation is 11 mrem. A 77 kg laboratory technician absorbs 2.3 mJ of 0.5 MeV gamma rays in a work day. The relative biological efficiency (RBE) for gamma rays is 1.00. The number of gamma-ray photons absorbed by the technician in a workday is closest to:
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The maximum permissible workday dose for occupational exposure to radiation is 18 mrem. A 54 kg laboratory technician absorbs 2.6 mJ of 0.3 MeV gamma rays in a work day. The relative biological efficiency (RBE) for gamma rays is 1.00. The ratio of the equivalent dosage received by the technician to the maximum permissible equivalent dosage is closest to:
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About how many days are required for a radioactive sample, with an initial activity of 105 Bq, to decay to an activity of 100 Bq? The half-life of the material is 4.5 days.
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A nuclear bomb explosion results in a mass decrease of about 2.10 g between the initial and the final ingredients. How much energy is released?
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The decay constant of a radioactive nuclide is 1.6 ×10-3s-1. At a given instant, the number of atoms of the radioactive nuclide is 1.85 ×1012. The number of atoms of the nuclide that remain after a time interval of 30 minutes is closest to:
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How much energy is released in the total fission of 2.0 g of 235U? The average energy per fission is 200.0 MeV.
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An air sample is contaminated with 15O, which has a half-life of 2.03 minutes. You can pass it through a long pipe to allow it to decay until it can be safely released, at an air speed of 1.1 m/s. How long must your pipeline be for the sample to decay to 3% of its original activity?
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The material used in nuclear bombs is 239Pu, with a half-life of about 20,000 years. How long must we wait for a buried stockpile of this substance to decay to 4% of its original 239Pu mass?
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Today, uranium contains 0.72% 235U (half-life = 0.70 billion years) and 99.28% 238U (half-life = 4.5 billion years). At a time 1.9 billion years ago, what was the fraction of 235U in uranium?
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An ancient rock is found to contain 40Ar gas, indicating that 77% of the 40K in the rock has decayed since the rock solidified. Any argon would have boiled out of liquid rock. How long ago did the rock solidify? The half-life of 40K is 1.25 billion years.
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The following masses are known: 1.008665 u 1.007825 u 226.025403 u The binding energy of , in MeV, is closest to: A) 1700 B) 1900 C) 2100 D) 2300 E) 2500
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A hospital patient has been given 131I (half-life = 8.04 days), which decays at 4.2 times the acceptable level for exposure to the general public. How long must the patient wait to reach the acceptable level? Assume that the material merely decays and is not excreted.
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An archaeologist finds the 14C in a sample of 3.10 g of material to be decaying at 107 counts per second. A modern 1.00-g sample of the same material decays at 151 counts per second. The half-life of 14C is 5730 years. How old is the sample?
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