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Ch.23 - Transition Metals and Coordination Chemistry
Chapter 23, Problem 16

Complete the exercises below. How many electrons are in the valence d orbitals in these transition-metal ions? a. Co³⁺, b. Cu⁺, c. Cd²⁺, d. Os³⁺.

Verified step by step guidance
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Step 1: Identify the electron configuration of the neutral atom for each transition metal. For example, cobalt (Co) has an atomic number of 27, so its electron configuration is [Ar] 3d^7 4s^2.
Step 2: Determine the electron configuration of the ion by removing electrons starting from the outermost shell. For Co³⁺, remove three electrons from the neutral Co configuration, starting with the 4s orbital, then the 3d orbital.
Step 3: Count the number of electrons remaining in the d orbitals after ionization. For Co³⁺, after removing three electrons, check how many are left in the 3d orbitals.
Step 4: Repeat the process for Cu⁺, which has a neutral electron configuration of [Ar] 3d^10 4s^1. Remove one electron to form Cu⁺ and count the electrons in the 3d orbitals.
Step 5: Apply the same method to Cd²⁺ and Os³⁺. For Cd, start with [Kr] 4d^10 5s^2 and remove two electrons. For Os, start with [Xe] 4f^14 5d^6 6s^2 and remove three electrons. Count the remaining d electrons for each ion.

Key Concepts

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

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. For transition metals, this involves filling the 3d and 4s orbitals. Understanding the electron configuration is crucial for determining the number of valence electrons in transition metal ions, especially when they lose electrons to form cations.
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Valence Electrons

Valence electrons are the outermost electrons of an atom and are involved in chemical bonding. In transition metals, the valence electrons include those in the s and d orbitals. Identifying the number of valence electrons in transition metal ions helps predict their chemical behavior and reactivity.
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Transition Metal Ions

Transition metal ions are formed when transition metals lose electrons, typically from their outermost s and d orbitals. The charge of the ion affects the electron count in these orbitals. Understanding how to determine the electron count in the d orbitals of these ions is essential for solving the given problem.
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