Chemistry » Chemical Bonding » Lewis Symbols and Structures

Lewis Symbols

Thus far in this tutorial, we have discussed the various types of bonds that form between atoms and/or ions. In all cases, these bonds involve the sharing or transfer of valence shell electrons between atoms. In this section, we will explore the typical method for depicting valence shell electrons and chemical bonds, namely Lewis symbols and Lewis structures.

Lewis Symbols

We use Lewis symbols to describe valence electron configurations of atoms and monatomic ions. A Lewis symbol consists of an elemental symbol surrounded by one dot for each of its valence electrons:

Lewis Symbols

The figure below shows the Lewis symbols for the elements of the third period of the periodic table.

Lewis Symbols

Lewis symbols illustrating the number of valence electrons for each element in the third period of the periodic table.

Lewis symbols can also be used to illustrate the formation of cations from atoms, as shown here for sodium and calcium:

Lewis Symbols

Likewise, they can be used to show the formation of anions from atoms, as shown here for chlorine and sulfur:

Lewis Symbols

The figure below demonstrates the use of Lewis symbols to show the transfer of electrons during the formation of ionic compounds.

Lewis Symbols

Cations are formed when atoms lose electrons, represented by fewer Lewis dots, whereas anions are formed by atoms gaining electrons. The total number of electrons does not change.

Do you want to suggest a correction or an addition to this content? Leave Contribution

[Attributions and Licenses]


This is a lesson from the tutorial, Chemical Bonding and you are encouraged to log in or register, so that you can track your progress.

Log In

Share Thoughts


Do NOT follow this link or you will be banned from the site!