The standard notation for the indication of the electronic configuration of atoms is written in a sequence of the label names of each atomic subshell with the number of electrons assigned to that specific subshell written in superscript.
These subshells are made up of atomic orbitals. The four subshell labels that are used are s, p, d, and f. The maximum number of electrons allowed in each of these subshells are 2, 6, 10, and 14 respectively.
For example, the names of the subshells in a sulfur atom would be 1s, 2s, 2p, 3s, and 3p (since sulfur has three electron shells). All of these shells are filled except the 3p shell which has four electrons. Therefore, the electronic configuration of sulfur can be written as 1s2 2s2 2p6 3s2 3p4.
The electronic configuration of elements can also be written with the help of noble gases. These noble gases have completely filled outermost shells and can be prefixed to the outermost shell of the element whose electronic configuration must be noted.
For example, the electronic configuration of sulfur can be written as [Ne] 3s2 3p4, since Neon has an electronic configuration of 1s2 2s2 2p6.
Electronic Configuration of First 30 Elements with Atomic Numbers
Given below is a table describing the electronic configuration of first 30 elements with atomic numbers.
|Atomic Number||Name of the Element||Electronic Configuration|
|3||Lithium (Li)||[He] 2s1|
|4||Beryllium (Be)||[He] 2s2|
|5||Boron (B)||[He] 2s2 2p1|
|6||Carbon (C)||[He] 2s2 2p2|
|7||Nitrogen (N)||[He] 2s2 2p3|
|8||Oxygen (O)||[He] 2s2 2p4|
|9||Fluorine (F)||[He] 2s2 2p5|
|10||Neon (Ne)||[He] 2s2 2p6|
|11||Sodium (Na)||[Ne] 3s1|
|12||Magnesium (Mg)||[Ne] 3s2|
|13||Aluminium (Al)||[Ne] 3s2 3p1|
|14||Silicon (Si)||[Ne] 3s2 3p2|
|15||Phosphorus (P)||[Ne] 3s2 3p3|
|16||Sulphur (S)||[Ne] 3s2 3p4|
|17||Chlorine (Cl)||[Ne] 3s2 3p5|
|18||Argon (Ar)||[Ne] 3s2 3p6|
|19||Potassium (K)||[Ar] 4s1|
|20||Calcium (Ca)||[Ar] 4s2|
|21||Scandium (Sc)||[Ar] 3d1 4s2|
|22||Titanium (Ti)||[Ar] 3d2 4s2|
|23||Vanadium (V)||[Ar] 3d3 4s2|
|24||Chromium (Cr)||[Ar] 3d5 4s1|
|25||Manganese (Mn)||[Ar] 3d5 4s2|
|26||Iron (Fe)||[Ar] 3d6 4s2|
|27||Cobalt (Co)||[Ar] 3d7 4s2|
|28||Nickel (Ni)||[Ar] 3d8 4s2|
|29||Copper (Cu)||[Ar] 3d10 4s1|
|30||Zinc (Zn)||[Ar] 3d10 4s2|
The electronic configuration of first 30 elements with atomic numbers listed above corresponds to the ground state of the specific elements. Any configuration that does not correspond to the lowest energy state is called an excited state. To learn more about writing the electronic configuration of an atom or a molecule, visit BYJU’S.