Subshells are made up of one or more atomic orbitals, while electron shells are made up of one or more subshells. The energy of electrons in the same subshell is the same, whereas electrons in various shells or subshells have different energies. The periodic table places elements in order depending on their atomic number, or how many protons they contain. Because the number of electrons in a neutral atom equals the number of protons, we can simply calculate electron number from atomic number. Furthermore, the column, or group, and row, or period, of an element in the periodic table provide useful information on how those electrons are grouped.

Electronic Configuration

The distribution of electrons in an atom’s orbitals is known as “electron configuration.” The principal energy level known as a shell is defined by a set of four quantum numbers n that defines an electron in an atom. The filling of electrons into different subshells s,p,d,fin an atom, also referred to as orbitals. The quantum numbers of the last orbital filled are used to identify an element’s periodic table location.

The electron configuration of an element describes the distribution of electrons in its atomic orbitals. Atomic electron configurations are written in a standard notation that arranges all electron-containing atomic subshells in a logical order (with the number of electrons they hold written in superscript). For example, sodium’s electron configuration is 1s²2s²2p²2p⁶3s¹.

The conventional notation, on the other hand, frequently results in extended electron configurations (especially for elements having a relatively large atomic number). In such instances, a shortened or condensed notation may be employed instead of the normal notation.

Purpose of Electron Configuration

Electron configurations have a wide range of applications, including:

• Determining the valency of an element
• Predicting the qualities of a group of elements (elements with similar electron configurations tend to exhibit similar properties)
• The study of atomic spectra and their interpretation
• After Ernest Rutherford and Niels Bohr developed the Bohr model of the atom in 1913, this notation for the distribution of electrons in atomic orbitals became popular

How to write electronic configuration

Shells

The primary quantum number determines the maximum number of electrons that may be accommodated in a shell n. It is represented by the formula 2n² where n is the shell number.

Subshells

• The subshells into which electrons are distributed are determined by the azimuthal quantum number (abbreviated as l)
• The value of the principal quantum number, n determines the value of this quantum number. As a result, when n equals 4, there are four separate subshells that can be created
• When n equals 4, The l=0,l=1,l=2,l=3values are represented by the s,p,d,fsubshells, respectively
• The maximum number of electrons that a subshell may hold is calculated using the formula 2*(2l+1)
• As a result, s,p,d,f subshells can only store 2,6,10,14 electrons, respectively

Notation

• Subshell labels are used to record the electron configuration of an atom.
• The shell number (determined by the primary quantum number), the subshell name (determined by the azimuthal quantum number), and the total number of electrons in the subshell (in superscript) are all included in these labels
• If two electrons are occupied in the s subshell of the first shell, the resultant notation is 1s²
• The electron configuration of magnesium (atomic number 12) can be expressed 1s² 2s²2p⁶3s² using these subshell labels

Shells and subshells

• Only a few particular energies are possible for electrons in atoms. The energy of electrons are quantized, as the name implies
• Electrons are grouped together into shells based on their energy (labeled by the principal quantum number, n). The higher the energy of a shell, the further it is from the nucleus (on average). Although electrons in higher-energy shells spend more time away from the nucleus than electrons in lower-energy shells, shells do not have particular, fixed distances from the nucleus
• Shells are further subdivided into subshells, which are subsets of electrons. There is just one subshell in the first shell, two in the second shell, three in the third shell, and so on. Each shell’s subshells are identified with the letterss,p,d,f, in that order. Thus, the first shell has simply a single s subshell (referred to as 1s), the second shell has 2s and 2psubshells, the third shell has 3s 3p 3dsubshells, and so on

Conclusion

Electron configurations provide insight into the chemical behaviour of elements by assisting in the determination of an atom’s valence electrons. It also aids in the division of components into distinct blocks (such as the s-block elements, the p-block elements, the d-block elements, and the f-block elements). This makes investigating the features of the components as a whole much easier.

Its electronic configuration is the regular distribution of electrons in the various atomic orbitals. We learnt about Electronic Configuration, shells or energy levels, and atomic structure . The valence shell is the atom’s outermost shell, and the electrons that make up the valence shell are known as valence electrons. Subshell labels are used to record the electron configuration of an atom. The electron configuration of an element describes the distribution of electrons in its atomic orbitals.