How to Draw Lewis Structure?

A Lewis electron dot structure illustrates the atoms involved in bonding, the number of bonds within the molecule, and the remaining unshared electrons on the bonding atoms.

To draw a Lewis structure, follow these steps:

1. Write the chemical formula for the molecule.
2. Determine the total number of valence electrons in the molecule. This can be done by adding up the number of valence electrons for each atom in the molecule.
3. Draw the skeleton structure of the molecule, with the atoms in their correct arrangement.
4. Place the valence electrons around the atoms. Each atom should have a full octet (8 electrons) in its outermost energy level.
5. Use single bonds to connect the atoms together.
6. If there are not enough electrons to give each atom a full octet, use double or triple bonds or a lone pair of electrons.
7. Make sure that the total number of electrons in the molecule is equal to the total number of valence electrons.
8. Check the Lewis Structure for any formal charge, which can be obtained by (number of valence electrons on free atom) – (nonbonding electrons + 1/2(bonding electrons))
9. If possible, adjust the structure to minimize the formal charge and stabilize the molecule.

We only consider valence electrons in Lewis Structure. Examples of Lewis structure of various compounds are,

Lewis Structure of N₂

• The atom of nitrogen contains 5 electrons in the valence shell.
• 2 of the five electrons exist in lone pairs and implying that nitrogen atom form 1 triple bond or 1 double bond and 1 single bond and 3 single bonds in order to become stable by attaining an octet configuration.
• So we have two nitrogen atoms that form 1 triple bond as shown in the figure to become stable.

Lewis structure of CO_2.

• The atom of carbon contains 4 electrons in the valence shell and oxygen contains 6 electrons in the valence shell.
• 4 of the 6 electrons of oxygen exist in lone pairs and implying that both oxygen atoms form 1 one bond with the carbon atom in order to become stable by attaining an octet configuration.
• So we have two oxygen atoms that form 1 double bond each with a carbon atom as the centre atom as shown in the figure to become stable.

Lewis Structure of O₂

• The atom of nitrogen contains 6 electrons in the valence shell.
• 4 of the 6 electrons exist in lone pairs and implying that oxygen atoms form 1 double bond and 2 single bonds in order to become stable by attaining an octet configuration.
• So we have two oxygen atoms that form 1 double bond as shown in the figure to become stable.

Lewis Structure of CO

• The atom of carbon contains 4 electrons in the valence shell and oxygen contains 6 electrons in the valence shell.
• 4 of the 6 electrons of oxygen exist in lone pairs and implying that oxygen atoms form 1 double bond and 2 single bonds in order to become stable by attaining an octet configuration.
• But this is an exceptional case the Lewis dot structure of the CO is shown in the figure.

Lewis Electron dot Structure is a type of representation of valence electrons of atoms and molecules and compounds with their bond structure. Atoms are the tiny particles of an element that are responsible for chemical reactions whereas, molecules are groups of atoms that are chemically bonded together. In this article, we will learn about, Lewis Electron Dot Structures in detail.