Textbook Question
Each of the following nuclei undergoes either beta decay or positron emission. Predict the type of emission for each: (b) 8938Sr.
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Ch.21 - Nuclear Chemistry
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232
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Table of contents
- Ch.1 - Introduction: Matter, Energy, and Measurement140
- Ch.2 - Atoms, Molecules, and Ions192
- Ch.3 - Chemical Reactions and Reaction Stoichiometry172
- Ch.4 - Reactions in Aqueous Solution156
- Ch.5 - Thermochemistry151
- Ch.6 - Electronic Structure of Atoms137
- Ch.7 - Periodic Properties of the Elements127
- Ch.8 - Basic Concepts of Chemical Bonding143
- Ch.9 - Molecular Geometry and Bonding Theories167
- Ch.10 - Gases147
- Ch.11 - Liquids and Intermolecular Forces97
- Ch.12 - Solids and Modern Materials129
- Ch.13 - Properties of Solutions126
- Ch.14 - Chemical Kinetics175
- Ch.15 - Chemical Equilibrium107
- Ch.16 - Acid-Base Equilibria127
- Ch.17 - Additional Aspects of Aqueous Equilibria133
- Ch.18 - Chemistry of the Environment88
- Ch.19 - Chemical Thermodynamics140
- Ch.20 - Electrochemistry137
- Ch.21 - Nuclear Chemistry99
- Ch.22 - Chemistry of the Nonmetals66
- Ch.23 - Transition Metals and Coordination Chemistry69
- Ch.24 - The Chemistry of Life: Organic and Biological Chemistry11
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook
Chapter 21, Problem 24
Despite the similarities in the chemical reactivity of elements in the lanthanide series, their abundances in Earth's crust vary by two orders of magnitude. This graph shows the relative abundance as a function of atomic number. Which of the following statements best explains the sawtooth variation across the series? (a) The elements with an odd atomic number lie above the belt of stability. (b) The elements with an odd atomic number lie below the belt of stability. (c) The elements with an even atomic number have a magic number of protons. (d) Pairs of protons have a special stability.
Verified step by step guidance1
Observe the graph showing the log of abundance in Earth's crust for lanthanides by atomic number. Note the sawtooth pattern in the data.
Identify that elements with even atomic numbers generally have higher abundances compared to their odd-numbered neighbors.
Recall that elements with even atomic numbers have paired protons, which contribute to their stability.
Understand that pairs of protons (even atomic numbers) have a special stability due to nuclear pairing effects, making them more abundant.
Conclude that the sawtooth variation in the graph is best explained by the special stability of pairs of protons, corresponding to option (d).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Lanthanide Series
The lanthanide series consists of 15 elements from lanthanum (La) to lutetium (Lu) in the periodic table. These elements are known for their similar chemical properties, including their reactivity and the presence of f-orbitals. Understanding the lanthanide series is crucial for analyzing their abundance and behavior in various chemical contexts, particularly in relation to their atomic structure and electron configurations.
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Stability and Abundance
The concept of stability in nuclear chemistry refers to the balance of forces within an atomic nucleus, which affects the likelihood of an element's occurrence in nature. Elements with certain 'magic numbers' of protons or neutrons exhibit enhanced stability, leading to higher relative abundances. This stability can explain the sawtooth variation in the abundance of lanthanides, as certain isotopes are more stable than others, influencing their presence in the Earth's crust.
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Odd-Even Effects
The odd-even effect in nuclear physics describes the phenomenon where nuclei with an odd number of protons or neutrons tend to be less stable than those with an even number. This effect can lead to variations in the abundance of elements, as odd-numbered lanthanides may have lower stability compared to their even-numbered counterparts. Recognizing this pattern is essential for understanding the sawtooth variation in the graph presented in the question.
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