Representation of Electronic Configuration

Electronic configuration of an atom is represented using a standardized notation system that indicates the distribution of electrons among the various atomic orbitals. Electronic Configurations are represented as follows:

• Shell Designation: Each electron shell is represented by a number ‘n’, where n= 1, 2, 3,….. This number corresponds to the principal quantum number.
• Subshell Designation: Each shell is further divided into different subshell that are represented using the notation of subshells (s, p, d, f).
• Orbital Filling Order: Electrons are then filled in orbitals from lowest energy orbital to highest according to Aufbau Principal. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.
• Electron Count: Number of electrons occupying each orbital is indicated by a superscript following the orbital designation. For example, 1s² represents that 1s orbital contains 2 electrons.

Writing Electron Configuration

For Writing Electron Configuration of an element, we must know the basic information about the element like atomic number, no. of electrons, shells, etc. The electronic configuration is typically represented using the notation of subshells (s, p, d, f) and the number of electrons in each subshell. For example, the potassium element has atomic number 19. And has 19 electrons which will be placed in s and p sub-shell. 

The electronic configuration can be written as 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹. Its 19 electrons can be divided into different shells in a manner,

• K shell (n = 1) = 2,
• L shell (n = 2) = 8,
• M shell (n = 3) = 8, and
• N shell (n = 4) = 1.

Electronic Configuration is the arrangement of electrons in orbitals around an atomic nucleus. Electronic Configuration of a molecule refers to the distribution of electrons in various molecular orbitals. The number of electrons in bonding and antibonding molecular orbitals of a molecule or molecular ion can be calculated from its electronic configuration.

In this article, we will learn about Electronic Configuration, Electronic Configuration in Periods, and Electronic Configuration in Groups.