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Ch.20 - Nuclear Chemistry
All textbooksMcMurry 8th EditionCh.20 - Nuclear ChemistryProblem 11
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Chapter 20, Problem 11

A sample 99mTc used for a whole body bone scan has an activity of 600 MBq. If the half-life is 6.01 hours, what mass of 99mTc was injected? (a) 3.1 ng (b) 8.4 microgram (c) 67 microgram (d) 2.7 mg

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1
Step 1: Understand the relationship between activity, decay constant, and number of atoms. The activity (A) of a radioactive sample is related to the number of radioactive atoms (N) and the decay constant (λ) by the equation A = λN.
Step 2: Calculate the decay constant (λ) using the half-life (t_{1/2}). The decay constant is given by the formula λ = \frac{0.693}{t_{1/2}}, where t_{1/2} is the half-life of the isotope.
Step 3: Rearrange the activity equation to solve for the number of atoms (N). Use the equation N = \frac{A}{λ}, where A is the activity of the sample.
Step 4: Convert the number of atoms (N) to moles. Use Avogadro's number (6.022 \times 10^{23} atoms/mol) to convert the number of atoms to moles.
Step 5: Calculate the mass of 99mTc. Use the molar mass of 99mTc (approximately 99 g/mol) to convert the moles of 99mTc to mass.
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Textbook Question
Calculate the binding energy a uranium-235 nucleus in units of MeV/nucleon. The mass of an 235U atom is 235.043 929, the mass of a proton is 1.007 28, the mass of a neutron is 1.008 67, and the mass of an electron is 5.486 x 10^-4. (1 MeV = 1.60 x 10^-13 J) (a) 2.84 MeV/nucleon (b) 1.70 x 10^3 MeV/nucleon (c) 11.3 MeV/nucleon (d) 7.62 MeV/nucleon
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Textbook Question
Identify the true statement about nuclear power plants and nuclear weapons. (a) Nuclear power plants and nuclear weapons both use uranium enriched to about 90% U-235. (b) Nuclear power plants emit large amounts of CO2 just like coal burning power plants. (c) The United States produces less than 1% of its electrical power from nuclear energy. (d) A nuclear weapon explodes when two pieces of fission-able uranium-235 are pushed together to reach a critical mass.
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Textbook Question
How much energy in kJ/mol is released by the fission of uranium-235 to form barium-140 and krypton-93? The atomic masses are (a) 6.59 x 10^9 kJ/mol (b) 1.66 x 10^10 kJ/mol (c) 1.98 x 10^11 kJ/mol (d) 1.66 x 10^16 kJ/mol
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Textbook Question

Complete and balance the following nuclear equations.

(d) <ISOTOPE CHEM REACTION>

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Textbook Question

Write balanced nuclear equations for the following processes.

(d) Positron emission of 165Ta

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Textbook Question
Isotope A decays to isotope E through the following series of steps, in which the products of the individual decay events are themselves radioactive and undergo further decay until a stable nucleus is ultimately reached. Two kinds of processes are represented, one by the shorter arrows pointing right and the other by the longer arrows pointing left. (b) Identify and write the symbol for each isotope in the series:

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