Textbook Question
For each of the following, indicate if the number of half-lives elapsed is:
1. one half-life
2. two half-lives
3. three half-lives
c. a sample of Au-198 with a half-life of 2.7 days after 5.4 days
Ch.5 Nuclear Chemistry
Timberlake14th EditionChemistry: An Introduction to General, Organic, and Biological ChemistryISBN: 9781292472249
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Table of contents
- Ch.1 Chemistry in Our Lives19
- Ch.2 Chemistry and Measurements80
- Ch.3 Matter and Energy53
- Ch.4 Atoms and Elements58
- Ch.5 Nuclear Chemistry42
- Ch.6 Ionic and Molecular Compounds57
- Ch.7 Chemical Quantities and Reactions38
- Ch.8 Gases30
- Ch.9 Solutions50
- Ch.10 Acids and Bases and Equilibrium64
- Ch.11 Introduction to Organic Chemistry: Hydrocarbons77
- Ch.12 Alcohols, Thiols, Ethers, Aldehydes, and Ketones82
- Ch.13 Carbohydrates54
- Ch.14 Carboxylic Acids, Esters, Amines, and Amides91
- Ch.15 Lipids61
- Ch.16 Amino Acids, Proteins, and Enzymes84
- Ch.17 Nucleic Acids and Protein Synthesis86
- Ch.18 Metabolic Pathways and ATP Production73
Timberlake14th EditionChemistry: An Introduction to General, Organic, and Biological ChemistryISBN: 9781292472249Not the one you use?Change textbook
Chapter 5, Problem 28a
Suppose a person absorbed 50 mrad of alpha radiation. What would be the equivalent dose in millisieverts?
Verified step by step guidance1
Step 1: Understand the relationship between absorbed dose (in rad) and equivalent dose (in sieverts). The equivalent dose is calculated using the formula: , where is the equivalent dose in sieverts, is the absorbed dose in grays, and is the radiation weighting factor.
Step 2: Convert the absorbed dose from millirads (mrad) to grays (Gy). Recall that 1 rad = 0.01 Gy, and 1 mrad = 0.00001 Gy. Multiply the given absorbed dose (50 mrad) by 0.00001 to convert it to grays.
Step 3: Identify the radiation weighting factor () for alpha radiation. Alpha particles have a weighting factor of 20 because they are highly ionizing.
Step 4: Multiply the absorbed dose in grays by the radiation weighting factor to calculate the equivalent dose in sieverts. Use the formula: .
Step 5: Convert the equivalent dose from sieverts to millisieverts (mSv). Recall that 1 sievert = 1000 millisieverts. Multiply the result in sieverts by 1000 to express the equivalent dose in millisieverts.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Radiation Dose
Radiation dose refers to the amount of energy deposited by ionizing radiation in a given mass of tissue. It is typically measured in grays (Gy) or rads, where 1 rad equals 0.01 Gy. Understanding radiation dose is crucial for assessing potential biological effects and risks associated with exposure.
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Intro to Radioactivity
Equivalent Dose
Equivalent dose is a measure that accounts for the biological effect of different types of radiation on human tissue. It is expressed in sieverts (Sv) or millisieverts (mSv) and is calculated by multiplying the absorbed dose by a radiation weighting factor, which varies depending on the type of radiation (e.g., alpha, beta, gamma).
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Radiation Weighting Factor
The radiation weighting factor is a numerical value that reflects the relative biological effectiveness of different types of radiation. For alpha particles, this factor is typically set at 20, meaning that alpha radiation is considered 20 times more effective at causing biological damage than gamma or beta radiation. This factor is essential for converting absorbed dose to equivalent dose.
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Related Practice
Textbook Question
Two samples of a radioisotope were spilled in a nuclear laboratory. The activity of one sample was 8 kBq and the other 15 mCi. Which sample produced the higher amount of radiation?
Textbook Question
The dosage of technicium-99m for a lung scan is 20. µCi/kg of body mass. How many millicuries of technicium-99m should be given to a person weighing 50. kg (1 mCi = 1000 µCi)
Textbook Question
Strontium-85, used for bone scans, has a half-life of 65 days.
b. How long will it take for the radiation level of strontium-85 to drop to one-eighth of its original level?
Textbook Question
Match each property (1 to 3) with its unit of measurement.
1. activity
2. absorbed dose
3. biological damage
a. rad
Textbook Question
Two technicians in a nuclear laboratory were accidentally exposed to radiation. If one was exposed to 8 mGy and the other to 5 rad, which technician received more radiation?