Question

The elements Si, Ga, As, Ge, Al, Cd, S, and Se are all used in the manufacture of various semiconductor devices. Write the expected electron configuration for these atoms.

Short answer

The electron configurations for the given elements are as follows: 1. Silicon (Si) - \(1s^2 2s^2 2p^6 3s^2 3p^2\) 2. Gallium (Ga) - \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^1\) 3. Arsenic (As) - \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^3\) 4. Germanium (Ge) - \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^2\) 5. Aluminum (Al) - \(1s^2 2s^2 2p^6 3s^2 3p^1\) 6. Cadmium (Cd) - \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10}\) 7. Sulfur (S) - \(1s^2 2s^2 2p^6 3s^2 3p^4\) 8. Selenium (Se) - \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^4\)

Step-by-step solution

Locate Elements in the Periodic Table

To find the elements' electronic configuration, we first need to find their position in the periodic table. Here are their positions in the format: Element (Period, Group): 1. Silicon (Si) - (3, 14) 2. Gallium (Ga) - (4, 13) 3. Arsenic (As) - (4, 15) 4. Germanium (Ge) - (4, 14) 5. Aluminum (Al) - (3, 13) 6. Cadmium (Cd) - (5, 12) 7. Sulfur (S) - (3, 16) 8. Selenium (Se) - (4, 16)

Write the Electron Configurations

Using the periodic table and the Aufbau principle, we can now write the electron configurations for each element: 1. Silicon (Si) - 1s² 2s² 2p⁶ 3s² 3p² 2. Gallium (Ga) - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p¹ 3. Arsenic (As) - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³ 4. Germanium (Ge) - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p² 5. Aluminum (Al) - 1s² 2s² 2p⁶ 3s² 3p¹ 6. Cadmium (Cd) - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 7. Sulfur (S) - 1s² 2s² 2p⁶ 3s² 3p⁴ 8. Selenium (Se) - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁴ These electron configurations describe the distribution of electrons in each element's atomic orbitals.

Key concepts

Understanding the Periodic Table

The periodic table is a comprehensive chart that organizes all known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number, which is the number of protons in an atom's nucleus.

The table is also structured in rows called periods and columns known as groups. Elements in the same group often have similar properties, including their valency and the type of chemical reactions they tend to participate in. For instance, group 1 elements, also known as alkali metals, are highly reactive and have a single electron in their outermost shell.

When it comes to understanding semiconductor devices, recognizing where these materials fall on the periodic table can give insights into their electronic properties. Semiconductors like silicon (Si) and germanium (Ge) sit in group 14, which are elements characterized by having four electrons in their outer energy level. This allows them to form covalent bonds and serves as the basis for their semiconducting behavior.

The Aufbau Principle

The Aufbau principle is a rule used in physics and chemistry to determine the electron configuration of an atom, ion, or molecule. It states that electrons fill atomic orbitals in a way to have the lowest possible energy states before filling higher states.

According to this principle, one must start at the lowest energy level (1s) and move up to higher energy levels progressively (2s, 2p, 3s, and so on). Keep in mind that sublevels also have an energy hierarchy; generally, the s sublevel is lower than the p, which is lower than the d, and this is lower than the f sublevel within the same principle energy level. This filling pattern is crucial for determining the electrostatic potential energy of an electron configuration.

For example, the correct electron configuration for aluminum (Al), following the Aufbau principle, begins with the lowest energy orbital (1s) and proceeds to fill up the next sublevels in order of increasing energy until all its 13 electrons have been distributed.

Semiconductor Devices and Electrons

Semiconductor devices are essential components in the modern electronic industry, pivotal in computers, smartphones, and various digital applications. These devices rely heavily on the behavior of electrons within semiconductor materials.

Semiconductors are materials with electrical conductivity between conductors (like copper) and insulators (like glass). This unique property comes from their electron configuration, which allows them to change their conductivity with the addition of energy – such as heat or light – or the introduction of impurities through a process called doping.

Understanding the electron configuration, particularly for elements like silicon (Si) and gallium (Ga), is fundamental. Silicon's electron configuration allows it to form bonds that create a lattice structure, with free electrons that can be mobilized under certain conditions. Gallium, when combined with arsenic to form gallium arsenide (GaAs), is used in high-speed electronics and optoelectronic devices because of desirable properties such as high electron mobility.

The versatility of electron configurations in semiconductor atoms underscores their role in designing a multitude of electronic devices. Knowledge of how these electrons can be manipulated is at the heart of advancing semiconductor technology.