Question

Which of the following species has the greatest number of unpaired electrons: \(\mathrm{S}^{+}, \mathrm{S},\) or \(\mathrm{S}^{-} ?\)

Short answer

\( S^{+} \) has the greatest number of unpaired electrons (3 unpaired electrons).

Step-by-step solution

Determine the Electron Configuration for Neutral Sulfur

Sulfur (\( S \)) has an atomic number of 16, which means it has 16 electrons in its neutral state. The electron configuration is 1\(s^2\) 2\(s^2\) 2\(p^6\) 3\(s^2\) 3\(p^4\).

Identify the Electron Configuration for \( \( S^{+} \) \)

\( S^{+} \) indicates a sulfur ion with one less electron than the neutral sulfur atom, hence it has 15 electrons. The electron configuration for \( S^{+} \) is 1\(s^2\) 2\(s^2\) 2\(p^6\) 3\(s^2\) 3\(p^3\).

Identify the Electron Configuration for \( S^{-} \)

\( S^{-} \) indicates a sulfur ion with one more electron than the neutral sulfur atom, so it has 17 electrons. The electron configuration for \( S^{-} \) is 1\(s^2\) 2\(s^2\) 2\(p^6\) 3\(s^2\) 3\(p^5\).

Determine the Number of Unpaired Electrons for Each Species

For \( S \): The 3\(p^4\) configuration has 2 unpaired electrons.For \( S^{+} \): The 3\(p^3\) configuration has 3 unpaired electrons.For \( S^{-} \): The 3\(p^5\) configuration has 1 unpaired electron.

Compare the Number of Unpaired Electrons

Compare the number of unpaired electrons in each species:\( S \) has 2, \( S^{+} \) has 3, and \( S^{-} \) has 1. Therefore, \( S^{+} \) has the greatest number of unpaired electrons.

Key concepts

Unpaired Electrons

Unpaired electrons are those that do not have a partner with opposite spin in an electron orbital. They are crucial because they determine the magnetic behavior of atoms and molecules. The presence of unpaired electrons makes a species paramagnetic, meaning they are attracted by a magnetic field. In contrast, paired electrons result in a species being diamagnetic, which means they are weakly repelled by magnetic fields.

When we look at the electron configurations of different sulfur species (\( S \), \( S^+ \), and \( S^- \)), each configuration can lead to different numbers of unpaired electrons. For example, in \( S \), the configuration \( 3p^4 \) results in two unpaired electrons. In \( S^+ \), the \( 3p^3 \) configuration results in three unpaired electrons, while in \( S^- \), the \( 3p^5 \) configuration has only one unpaired electron. This example demonstrates how slight changes in electron count can impact the physical properties of a species related to magnetism.

Sulfur Ion

Sulfur ions form when the neutral sulfur atom gains or loses electrons. This process alters its electronic configuration and changes its chemical properties.

The sulfur ion \( S^+ \) is created when sulfur loses one electron, giving it the electron configuration of \( 1s^2 2s^2 2p^6 3s^2 3p^3 \). This leads to an increase in unpaired electrons, creating a situation where the ion has three unpaired electrons. Conversely, the \( S^- \) ion forms when sulfur gains an extra electron, resulting in the configuration \( 1s^2 2s^2 2p^6 3s^2 3p^5 \), with only one unpaired electron.

These ionic forms illustrate how altering the number of electrons directly impacts the chemical and magnetic nature of sulfur, emphasizing the importance of ions in understanding elemental behavior.

Atomic Number

The atomic number is a fundamental property of an element, representing the number of protons in an atom's nucleus. This number also tells us the number of electrons in a neutral atom, which determines the element’s electron configuration. Sulfur, for instance, has an atomic number of 16. In its neutral state, it has 16 electrons.

The atomic number allows us to identify elements on the periodic table and predict their chemical behavior. For sulfur, knowing the atomic number is essential in determining its various electron configurations and understanding how it behaves when it forms \( S^+ \) and \( S^- \) ions. Changes in electron count due to ionization result in altered configurations and, consequently, different numbers of unpaired electrons in each state.

Electron Configuration Notation

Electron configuration notation is a method used to represent the distribution of electrons around an atom's nucleus. This notation involves writing the energy levels, sublevels, and the number of electrons in each, such as \( 1s^2 2s^2 2p^6 3s^2 3p^4 \) for neutral sulfur.

This notation is important because it provides a systematic way to understand how electrons are arranged and helps predict how atoms will interact chemically. Understanding electron configurations can show potential bonding capabilities and determine the number of unpaired electrons which influence chemical reactivity and magnetic properties.

• For neutral sulfur (\( S \)), the configuration \( 3p^4 \) shows that there are two unpaired electrons.
• In \( S^+ \), \( 3p^3 \) results in three unpaired electrons.
• For \( S^- \), the \( 3p^5 \) configuration leaves only one unpaired electron.

Utilizing electron configuration notation simplifies the process of predicting atomic behavior under different conditions.