Exam 19: Nuclear Chemistry: Applications to Energy and Medicine

In the initial sequence of thorium-232 decay, an alpha particle is emitted followed by a beta particle. What is the product of these two decay steps?

Which of the following units is used to quantify the biological effects of radiation?

Polonium-210 is a radioactive isotope that was used as a fatal toxin in the poisoning of Alexander Litvinenko, a former KGB agent, in 2006. What type of emission process is likely for this isotope?

A number of techniques are used for diagnostic imaging of internal body organs. Which of these involve ionizing radiation and therefore pose a risk for cancer? I. CT scan (X-ray computed tomography) II. MRI scan (radio-wave magnetic resonance imaging) III. US scan (ultrasound) IV. Nuclear heart scan (radioactive tracer) V. EKG (electrocardiograph)

The peak in nuclear binding energy/nucleon occurs for an isotope of ________

Artificial sources account for approximately ________ of annual radiation exposure to a human.

Low-level nuclear waste from medical facilities generally requires only short-term storage before disposal because ________

A half-life is ________

Light elements with Z  20 generally have a neutron/proton ratio about equal to ________

Radiation seed therapy is a common method for treating some prostate cancers and brain tumors. Cesium-131, which decays by electron capture and gamma ray emission with a half-life of 9.69 days, is a new isotope proposed for such treatment. If a tumor were seeded with 1.00 g of cesium-131 (130.91 g/mol), what would the initial radioactivity level be? Note: 1 Ci = 3.70  10¹⁰/s.

A number of techniques are used for diagnostic imaging of internal body organs. Which of these do not involve ionizing radiation and therefore do not pose a risk for producing cancer? I. CT scan (X-ray computed tomography) II. MRI scan (radio-wave magnetic resonance imaging) III. US scan (ultrasound) IV. Nuclear heart scan (radioactive tracer) V.EKG (electrocardiograph)

Which of the following is not true about radon gas? I. Damage from radon stems from radioactive decay rather than the toxicity of the gas itself. II. Radon gas is a potential danger in well-insulated homes. III. Uranium-238 in the soil generates radon gas through radioactive decay. IV. Radon-222 and its decay product emit  particles that can damage the lungs.

A nerdy Scotch-drinking physicist, Nicola, suspected that the 50-year-old Scotch she purchased was misrepresented. Reasoning that water must contain the radioactive hydrogen isotope, tritium, because this isotope is produced in the atmosphere by cosmic rays, she decided she could use the tritium concentration in the Scotch to determine when it was bottled. She found that the tritium concentration in the Scotch was only 64% that of the tritium concentration in the water on the Isle of Islay where the Scotch was bottled. How old, really, was this 50-year-old Scotch? The half-life of tritium is 12.3 years.

In 2002, a wooden beam from the Wupatki Indian ruin in Arizona was found to contain 235 mg of carbon-14. A sample of wood of the same mass cut sometime in 2002 contained 264 mg of carbon-14. When was the beam from Wupatki cut if the half-life of carbon-14 is 5,715 years?

Nuclear fusion produces energy because ________

If a nitrogen-14 nuclide captures an alpha particle, a proton is produced along with ________

Plutonium-238 is an  emitter and a compact heat source. Coupled with a PbTe thermoelectric device, it was once used as a very reliable electrical energy source for cardiac pacemakers. What is the product of the radioactive decay of plutonium-238?

Provide three examples of artificial radiation sources to which humans are exposed. Do these constitute the majority or minority of human radiation exposure?

Radiation seed therapy is a common method for treating some prostate cancers and brain tumors. Palladium-103 is one isotope used for this treatment. Palladium-103 decays with a half-life of 17 days by emitting X-rays with a photon energy of 23,000 eV. What mass of palladium-103 would have to be embedded in a 25 g tumor to produce a radiation dose of 125 Gy in 2 months' time (60 days)? Note: 1 Gy = 1 J/kg, and 1 eV = 1.60  10^19 J.

Radiation seed therapy is a common method for treating some prostate cancers and brain tumors. Iodine-125, with a half-life of 60 days, is one isotope used for this treatment. How long does it take for the activity of iodine-125 to decrease to 5.0% of its initial value?