Ionic compounds are the ones that are formed by the transfer of one or more electrons from one atom to other among them. We cannot see the interior of a compound, but we can definitely draw its structure. Lewis structures are one of the visualization of the compounds and bonds formed among different atoms through dots that represent their electronic configurations, lone pairs, and bond pairs. In this article, we will talk about in general what is a Lewis structure and how to draw Lewis structure of ionic compounds.
1. What is a Lewis Dot Structure? A Lewis structure is named after Gilbert Lewis, who first proposed it in 1916. Lewis structures add lines between atoms to represent shared pairs in a chemical bond, extending the concept of the electron dot diagram.
1.1 What does a Lewis Dot Structure Represent? A Lewis structure is a type of diagram that is used to represent the electron configuration of a molecule or ion. It generally represents the following things:
The structure consists of a skeletal structure of the molecule, with atoms represented by their chemical symbols and electrons represented by dots.
The dots are placed around the chemical symbols to show the distribution of electrons in the molecule.
The number of dots around an atom represents the number of electrons that are available for bonding with other atoms in the molecule.
The Lewis structure is useful for predicting the geometric shape of a molecule and the chemical properties of its bonds.
2. How to Draw Lewis Dot Structure? We use the symbol of an element to represent an electron dot structure. The valence electrons are represented by dots that are added clockwise to an element's chemical symbol. There can be a maximum of eight dots. This ensures that the octet rule may be followed, which only allows for a maximum of eight valence electrons. For a Lewis dot structure, the octet rule is important. According to the octet rule, atoms tend to gain, lose, or share valence electrons in order to achieve a noble gas configuration, which gives the atom stability. The octet rule only takes into account the s and p electrons; it ignores the d and f electrons.
3. Lewis Structure for Ionic Compounds In ionic compounds, valence electrons are transferred from the metal to the non-metal. Therefore, an ionic compound consists of a cation which is formed by losing its valence electrons, and an anion which is formed by accepting electrons to attain stability. The Lewis structure of an ionic compound represents the distribution of electrons in the compound. The Lewis structure of an ionic compound is not necessarily a single molecule but rather a repeating pattern of cations and anions arranged in a crystal lattice.
3.1 Lewis Structure of a Cation In the case of a cation, the Lewis structure shows the loss of one or more electrons from the neutral atom, resulting in a positive charge.
3.2 Lewis Structure of an Anion For an anion, the Lewis structure shows the gain of one or more electrons by the neutral atom, resulting in a negative charge.
Examples Ionic compounds can be represented by the Lewis Dot Structures, considering that a positive charge indicates that electrons have been lost. In contrast, a negative charge indicates that additional electrons have been gained. Lewis Dot Structures for ionic compounds are always encased in brackets, with the charge displayed on the exterior. Some examples of the Lewis structure of Ionic compounds are given below.
The number of valence electrons surrounding an atom or molecule can be determined using Lewis structures.
It provides information on the type of bond and the lone pair of electrons that are distributed throughout the involved atoms.
The valence electrons are represented by dots that are added clockwise to an element's chemical symbol.