Problem 85 - Chemistry The Molecular Science

Question

Give the electron configuration of (a) \(\mathrm{Ti}^{3+}\). (b) \(\mathrm{V}^{2+}\) (c) \(\mathrm{Ni}^{3+}\). (d) \(\mathrm{Cu}^{+}\).

Step-by-Step Solution

Answer

(a) \([\text{Ti}^{3+}: 3d^1]\); (b) \([\text{V}^{2+}: 3d^3]\); (c) \([\text{Ni}^{3+}: 3d^7]\); (d) \([\text{Cu}^+: 3d^{10}]\)

Step 1: Determine the Neutral Atom's Electron Configuration

First, we find the electron configuration for the neutral atoms of Ti, V, Ni, and Cu. - **Ti (Titanium)**: Atomic number is 22, so the electron configuration is: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^2 \]- **V (Vanadium)**: Atomic number is 23, so the electron configuration is: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^3 \]- **Ni (Nickel)**: Atomic number is 28, so the electron configuration is: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^8 \]- **Cu (Copper)**: Atomic number is 29, so the electron configuration is: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 3d^{10} \] (because of the energy stabilization by fully filling the 3d orbital).

Step 2: Adjust for Ionization Loss of Electrons

After determining the electron configuration for the neutral atom, we account for the loss of electrons due to ionization. Electrons are removed starting from the outermost shell, which typically involves the 4s electrons before 3d electrons for transition metals.(a) **\(\mathrm{Ti}^{3+}\)**: Remove three electrons from the neutral Ti electron configuration:\[\text{Remove: } 4s^2 \text{ and }1\; 3d^1\]Configuration: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^1 \](b) **\(\mathrm{V}^{2+}\)**: Remove two electrons from the neutral V configuration:\[\text{Remove: } 4s^2 \]Configuration: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^3 \](c) **\(\mathrm{Ni}^{3+}\)**: Remove three electrons from the neutral Ni configuration:\[\text{Remove: } 4s^2 \text{ and }1\; 3d^7\]Configuration: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^7 \](d) **\(\mathrm{Cu}^{+}\)**: Remove one electron from the neutral Cu configuration:\[\text{Remove: } 4s^1 \]Configuration: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} \]

Key Concepts

Transition Metals

Transition metals are unique elements found in the d-block of the periodic table. They are often recognized for their ability to form various oxidation states. This flexibility arises from the similar energy levels of their outer s and d electron shells. These metals include familiar elements like iron, copper, and nickel, known for their widespread industrial use.

Key characteristics of transition metals include:

• Variable oxidation states: Transition metals can lose a different number of electrons, leading to ions with varying charges.
• Metallic properties: These elements are good conductors of electricity and are often malleable and ductile.
• Formation of colored compounds: Their ability to form various coordination complexes results in vibrant colors.

Understanding transition metals involves looking into their electron configurations, which dictate their chemical behavior and reactivity.

Ionic Charge

The concept of ionic charge is crucial for understanding how atoms transform into ions. Ions occur when an atom gains or loses electrons, resulting in a net positive or negative charge.

Here’s how it works:

• A positive ion, or cation, forms when an atom loses electrons. Metals, including transition metals, commonly form cations.
• A negative ion, or anion, is created when an atom gains electrons. This is less common for metals.

Ionic charges directly affect the electrical neutrality of compounds and play a vital role in determining their chemical properties. For example, transition metals like titanium (\(\mathrm{Ti}^{3+}\)) and copper (\(\mathrm{Cu}^{+}\)) adjust their electron counts to achieve stable configurations.

Electron Removal

Electron removal is a key idea when working with ions, particularly transition metals. It refers to the process of losing electrons to form cations. For transition metals, the electrons in the outermost shell are removed first. Typically, electrons are lost from the 4s orbital before the 3d orbital despite being filled later.

Here's a simple approach to understand electron removal:

• Determine the neutral atom’s electron configuration.
• Remove the necessary number of electrons based on the ion's charge.
• Follow the rule that 4s electrons are removed before 3d electrons in transition metals.

This method helps determine the electron configuration of ions, like \(\mathrm{Ni}^{3+}\), where three electrons are removed resulting in a \(3d^7\) configuration.

Electron Shells

Electron shells are layers around the nucleus where electrons reside, each with a specific energy level. These shells play a fundamental role in determining an atom's electron configuration and, consequently, its chemical behavior.

Things to note about electron shells:

• Each shell can hold a maximum number of electrons, calculated using \(2n^2\), where \(n\) is the shell level.
• The innermost shell (1s) fills first, followed by subsequent shells (2s, 2p, etc.).
• Transition metals often have complex filling sequences around the 3d and 4s orbitals.

Understanding electron shells is crucial for predicting how transition metals like \(\mathrm{V}^{2+}\) arrange their electrons during ionization, maintaining as stable and low-energy a configuration as possible.