Write the nuclear equation for the most likely mode of decay for each unstable nuclide. a. Ru-114 c. Zn-58 d. Ne-31
Ch.20 - Radioactivity and Nuclear Chemistry
Chapter 20, Problem 75
PET studies require fluorine-18, which is produced in a cyclotron and decays with a half-life of 1.83 hours. Assuming that the F-18 can be transported at 60.0 miles/hour, how close must the hospital be to the cyclotron if 65% of the F-18 produced makes it to the hospital?
Verified step by step guidance1
insert step 1: Understand the problem by identifying the key information: the half-life of fluorine-18 (1.83 hours), the transportation speed (60.0 miles/hour), and the requirement that 65% of the F-18 must reach the hospital.
insert step 2: Use the concept of half-life to determine the decay constant (k) using the formula: k = \(\frac{0.693}{t_{1/2}\)}, where t_{1/2} is the half-life.
insert step 3: Calculate the time (t) it takes for the F-18 to decay to 65% of its original amount using the first-order decay equation: N_t = N_0 e^{-kt}, where N_t/N_0 = 0.65.
insert step 4: Solve for t in the equation from step 3 to find the time it takes for the F-18 to decay to 65% of its original amount.
insert step 5: Calculate the maximum distance the F-18 can be transported by multiplying the time (t) from step 4 by the transportation speed (60.0 miles/hour).
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Half-life
Half-life is the time required for half of a sample of a radioactive substance to decay. In this case, fluorine-18 has a half-life of 1.83 hours, meaning that after this time, only 50% of the original amount remains. Understanding half-life is crucial for calculating how much F-18 will be available when it reaches the hospital.
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Radioactive decay
Radioactive decay is the process by which an unstable atomic nucleus loses energy by emitting radiation. This process is random and can be quantified using the half-life. For the PET studies, knowing the decay rate of fluorine-18 helps determine how much of the isotope will still be viable upon arrival at the hospital.
Distance and time calculation
Calculating the distance based on speed and time involves using the formula distance = speed × time. In this scenario, the speed of transport is given as 60.0 miles/hour, and the time until a significant amount of F-18 decays must be calculated based on its half-life. This concept is essential for determining how far the hospital can be from the cyclotron while still receiving an effective dose of F-18.
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Related Practice
Textbook Question
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Textbook Question
Complete each nuclear equation and calculate the energy change (in J/mol of reactant) associated with each (Al-27 = 26.981538 amu, Am-241 = 241.056822 amu, He-4 = 4.002603 amu, Np-237 = 237.048166 amu, P-30 = 29.981801 amu, S-32 = 31.972071 amu, and Si-29 = 28.976495 amu).
a. 2713Al + 42He → 3015P + ____
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Textbook Question
A 75-kg human has a dose of 32.8 rad of radiation. How much energy is absorbed by the person's body? Compare this energy to the amount of energy absorbed by the person's body if he or she jumped from a chair to the floor (assume that the chair is 0.50 m from the ground and that all of the energy from the fall is absorbed by the person).
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