Question

The ground-state electron configurations listed here are incorrect. Explain what mistakes have been made in each and write the correct electron configurations. Al: \(1 s^{2} 2 s^{2} 2 p^{4} 3 s^{2} 3 p^{3}\) B: \(1 s^{2} 2 s^{2} 2 p^{5}\) \(\mathrm{F}: 1 s^{2} 2 s^{2} 2 p^{6}\)

Short answer

Al: \(1s^2 2s^2 2p^6 3s^2 3p^1\); B: \(1s^2 2s^2 2p^1\); F: \(1s^2 2s^2 2p^5\)

Step-by-step solution

Identify Errors in Aluminum's Configuration

Aluminum's given electron configuration is \(1s^2 2s^2 2p^4 3s^2 3p^3\). Notice that for the second shell, \(2p^4\) implies that there are only 4 electrons in the \(2p\) sublevel, which can hold a maximum of 6 electrons. The third shell configuration \(3s^2 3p^3\) combined with \(2p^4\) incorrectly totals to 13 electrons, while Aluminum has an atomic number of 13 and should follow the correct sequential filling order.

Correct Aluminum's Configuration

The correct configuration for Aluminum (Al, atomic number 13) should fill the sublevels in order: \(1s^2 2s^2 2p^6 3s^2 3p^1\). This reflects the fill order up through \(3p\) and the respective sublevel capacities.

Identify Errors in Boron's Configuration

Boron has been given the configuration \(1s^2 2s^2 2p^5\). The total number of electrons sums incorrectly to 9. Boron actually has an atomic number of 5, which means only 5 electrons need to be accounted for with a full \(1s\) and a partial \(2p\) sublevel.

Correct Boron's Configuration

The correct electron configuration for Boron is \(1s^2 2s^2 2p^1\). This configuration correctly reflects the placement of Boron's 5 electrons: 2 in \(1s\), 2 in \(2s\), and 1 in \(2p\).

Identify Errors in Fluorine's Configuration

Fluorine is shown with the configuration \(1s^2 2s^2 2p^6\). Totals to 10 electrons; however, Fluorine has an atomic number of 9. The \(2p\) sublevel in the given configuration is overfilled by 1 electron.

Correct Fluorine's Configuration

The correct configuration for Fluorine is \(1s^2 2s^2 2p^5\). This counts the correct number of electrons in the filled shells, with 2 in \(1s\), 2 in \(2s\), and 5 in \(2p\) for a total of 9 electrons.

Key concepts

Quantum Mechanics

Quantum mechanics plays a vital role in understanding electron configurations, particularly when it comes to describing electron behavior. This branch of physics explains how electrons move within an atom's structure through wave functions and probability. By using quantum mechanics, scientists can predict electron positions and their energy levels with great accuracy. - According to quantum mechanics, electrons exist in discrete energy levels or "quantized" states. - Electrons are described by four quantum numbers: principal (n), azimuthal (l), magnetic (m_l), and spin (s). - Each electron's unique set of quantum numbers helps explain their position and behavior. Understanding quantum mechanics allows for the prediction of elements' chemical properties by examining electron configurations. It provides a framework for how electrons arrange themselves in shells and sublevels, influencing how atoms interact with one another in chemical reactions.

Atomic Structure

The atomic structure is fundamental in understanding electron configurations. An atom is composed of a nucleus, made of protons and neutrons, with electrons orbiting around it in various energy levels. These electrons tend to fill the lowest energy levels first before moving to higher ones. - The number of protons in the nucleus determines the element's identity and is reflected in its atomic number. - Electrons, charged negatively, balance out the positive charge of protons. - The arrangement of electrons around the nucleus follows the principle of energy minimization, aiming to achieve the most stable configuration. Understanding the basic atomic structure helps in grasping how electrons fill the various orbitals and how this influences an element's chemical behavior. The atomic structure provides a groundwork for predicting interaction patterns in chemical processes.

Periodic Table

The periodic table is a critical tool for predicting electron configurations. It organizes elements based on their atomic numbers and electron configurations, allowing for easy identification of an element's properties. Each element's position in the table gives clues about its electron structure, reflecting similarities and trends across periods and groups. - Elements in the same group have similar electron configurations in their outermost shells, leading to similar chemical properties. - Moving left to right across a period, electrons are added to the same shell, increasing atomic number and filling orbitals in sequence. - The table is divided into blocks (s, p, d, and f) that correlate with the filling orders of electron sublevels. By using the periodic table, one can quickly determine the correct electron configuration of an element, check for valence electrons, and understand its chemical reactivity and bonding possibilities.

Electron Shells

Electron shells are levels where electrons orbit around an atom's nucleus. Each shell can hold a limited number of electrons, following the order of principal quantum numbers. Understanding electron shells is crucial for writing correct electron configurations and predicting element behavior. - Shells are labeled by principal quantum numbers (n=1, 2, 3,...), with each shell further divided into subshells (s, p, d, f). - The s subshell holds up to 2 electrons, p holds 6, d holds 10, and f can hold 14 electrons. - Electrons fill the lowest-energy available subshells first, following **the Aufbau principle**, moving layer by layer. Electron configuration errors occur when electrons are incorrectly distributed among shells. By understanding the proper distribution rules, one can correctly write configurations, identify mistakes in listing, and grasp chemical properties influenced by electron arrangements.