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Ch.7 - Periodic Properties of the Elements
All textbooksBrown 14th EditionCh.7 - Periodic Properties of the ElementsProblem 87
Chapter 7, Problem 87

Elements in group 17 in the periodic table are called the halogens; elements in group 16 are called the chalcogens. For each of the following periodic properties, state whether the halogens or the chalcogens have larger values: atomic radii, ionic radii of the most common oxidation state, first ionization energy, and second ionization energy.

Verified step by step guidance
1
Identify the position of halogens and chalcogens in the periodic table. Halogens are in group 17, while chalcogens are in group 16.
Understand atomic radii trends: Atomic radii increase as you move down a group and decrease as you move across a period from left to right. Therefore, compare the atomic radii of halogens and chalcogens based on their position in the periodic table.
Consider ionic radii: The most common oxidation state for halogens is -1, while for chalcogens it is -2. Ionic radii generally increase with higher negative charge due to increased electron-electron repulsion. Compare the ionic radii of halogens and chalcogens in their most common oxidation states.
Examine first ionization energy: Ionization energy generally increases across a period from left to right and decreases down a group. Compare the first ionization energies of halogens and chalcogens based on their position in the periodic table.
Analyze second ionization energy: The second ionization energy is the energy required to remove a second electron after the first has been removed. Consider the electron configuration and stability of the resulting ions to compare the second ionization energies of halogens and chalcogens.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Periodic Trends

Periodic trends refer to predictable patterns in the properties of elements as you move across or down the periodic table. Key trends include atomic radius, ionization energy, and electronegativity. Understanding these trends helps in comparing elements in the same group or period, such as the halogens and chalcogens, and predicting their behavior in chemical reactions.
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Periodic Trends

Atomic and Ionic Radii

Atomic radius is the distance from the nucleus to the outermost electron shell, while ionic radius refers to the size of an ion in a crystal lattice. Generally, atomic and ionic radii increase down a group due to the addition of electron shells, and decrease across a period due to increased nuclear charge. This concept is crucial for comparing the sizes of halogens and chalcogens.
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Ionization Energy

Ionization energy is the energy required to remove an electron from an atom or ion. It typically increases across a period due to greater nuclear charge and decreases down a group as the outer electrons are further from the nucleus. Understanding ionization energy is essential for comparing the reactivity and stability of halogens and chalcogens in their common oxidation states.
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Related Practice
Textbook Question

The As ¬ As bond length in elemental arsenic is 2.48 Å. The Cl ¬ Cl bond length in Cl2 is 1.99 Å. (a) Based on these data, what is the predicted As ¬ Cl bond length in arsenic trichlo- ride, AsCl3, in which each of the three Cl atoms is bonded to the As atom?

Textbook Question

The As ¬ As bond length in elemental arsenic is 2.48 Å. The Cl ¬ Cl bond length in Cl2 is 1.99 Å. (b) What bond length is predicted for AsCl3, using the atomic radii in Figure 7.7?

Textbook Question
The following observations are made about two hypotheticalelements A and B: The A¬A and B¬B bond lengths in theelemental forms of A and B are 236 and 194 pm, respectively.A and B react to form the binary compound AB2, which hasa linear structure (that is B-A-B = 180°). Based on thesestatements, predict the separation between the two B nucleiin a molecule of AB2.
Textbook Question

Elements in group 7A in the periodic table are called the halogens; elements in group 6A are called the chalcogens. (a) What is the most common oxidation state of the chalcogens compared to the halogens?

Textbook Question
Note from the following table that there is a significant increasein atomic radius upon moving from Y to La, whereasthe radii of Zr to Hf are the same. Suggest an explanation forthis effect.Atomic Radii (pm)Sc 170 Ti 160Y 190 Zr 175La 207 Hf 175