Exam 19: Nuclear Chemistry: Applications to Energy and Medicine

Two of the units used to measure biological effects of radioactivity are sievert and rem. What are these units used to measure?

The isotope "belt of stability" is an area in a plot of ________

Uranium-238 ( ) decays to form thorium-234 ( ) with a half-life of 4.5  10 ⁹ years. How many years will it take for 75% of the uranium-238 to decay?

Which process is not part of the pathway that produces ⁴He nuclides in our sun?

Which reactant and product would balance the following nuclear reaction equation? reactant  ¹² C  ¹¹B  product

When carbon and oxygen combine in a combustion reaction, 394 kJ of energy are released for each mole of carbon dioxide that is produced. Compare this amount with the energy released in our sun when 1 mole of helium-4 is produced from 4 protons.

Crews of commercial airlines are exposed to a higher level of background cosmic radiation during flight time than they would receive on the ground. A single round-trip, coast-to-coast flight gives a dose of about 0.012 rems. If a stewardess made 200 such flights in one year, how would her annual dose compare with a normal annual exposure on the ground of 3.6 mSv? (100 rem = 1 Sv)

Which process converts a proton into a neutron?

Calculate the nuclear binding energy per nucleon for the copper-63 isotope. Here are some helpful data:

Though uranium-238, an alpha emitter, is radioactive, it can be worked with safely in a glovebox with no additional precautions. Offer an explanation.

Uranium-238 decays to lead-206 through a series of nuclear reactions. Only  particles and particles are emitted. How many  particles are emitted?

Prozac (fluoxetine hydrochloride) is a selective serotonin reuptake inhibitor (SSRI) used to treat depression. Its function in the brain can be studied by using radiolabeled ¹⁸F instead of natural abundance fluorine in its structure. The positron emission is detected by a PET scan. The half-life of ¹⁸F is 109.7 minutes. If radiolabeled Prozac were administered to a patient for a PET scan at 8:00 A.M. on Monday, at what time would its activity reach 10% of the original activity?

Radiation seed therapy is a common method for treating some prostate cancers and brain tumors. Iodine-125, which decays by electron capture followed by gamma ray emission with a half-life of 59.4 days, is one isotope used for this treatment. If a tumor were seeded with 1.00 g of iodine-125 (124.90 g/mol), what would the initial radioactivity level be? Note: 1 Ci = 3.70  10¹⁰/s.

Radiation seed therapy is a common method for treating some prostate cancers and brain tumors. Palladium-103, which decays by electron capture and gamma ray emission with a half-life of 17.0 days, is one isotope used for this treatment. How much palladium-103 (102.91 g/mol) is needed to produce an initial radioactivity level of 1.30 mCi? Note: 1 Ci = 3.70  10¹⁰/s.

Which element has stable isotopes with the largest ratio of neutrons to protons?

Nuclear fission produces energy because ________

What units are used to measure the activity of a radioactive sample?

Particles emitted in radioactive decay have different penetrating power. The penetration depths of two particles, labeled X and Y, in a column of water are shown below. Which of the following statements could not be true?

Small traces of radioactive substances, mainly from the food we eat, are present in the human body. The most abundant radioisotope in the body is potassium-40. A person weighing 70 kg contains about 150 g of potassium, and about 0.01% of this amount is potassium-40. The half-life of potassium-40 is 1.25 10⁹ years. Estimate the rate at which radiation is produced by the decay of potassium-40 in the body.

Among other problems with smoking, there is a danger from radiation, according to the following report. "Tobacco plants are grown in soils with high phosphate fertilizers that are naturally contaminated with the alpha-particle emitting radionuclide polonium-210. In one year, the average smoker will irradiate the bronchial epithelium with 8 to 9 rem, the equivalent dose of radiation from 250 to 300 chest X-ray films per year" (Pediatrics, September 1993, p. 464). How does this annual dose from tobacco compare to an average annual dose of 3.6 mSv that a nonsmoker receives from background radiation? (1 Sv = 100 rem)