Lewis structures

Definition

Lewis structures are diagrams used to represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They help visualize the arrangement of valence electrons around atoms.

5 Must Know Facts For Your Next Test

1. Lewis structures show how valence electrons are arranged among atoms in a molecule.
2. The octet rule is often used, stating that atoms tend to form bonds until they have eight electrons in their valence shell.
3. Lewis structures can indicate possible resonance structures for certain molecules.
4. A double bond consists of two shared pairs of electrons, whereas a triple bond consists of three shared pairs.
5. Lone pairs are non-bonding pairs of electrons shown as dots on individual atoms.

Review Questions

• What is the primary purpose of a Lewis structure?
• How do you determine the number of valence electrons to use when drawing a Lewis structure?
• What is the difference between bonding pairs and lone pairs in Lewis structures?

Related terms

Octet Rule:

A chemical rule of thumb that reflects an atom's tendency to prefer having eight electrons in its valence shell.

Resonance: A concept where two or more valid Lewis structures can be drawn for the same molecule, representing delocalized electrons.

Valence Electrons:

The outermost electrons of an atom that are involved in forming bonds.