Lewis structures

High School

Definition

Diagrams that show how atoms are bonded in a molecule and where any lone pairs of electrons are located, using dots and lines to represent electrons. Lewis structures help predict the shape and reactivity of molecules.

Worked examples

\(\)H\(_2\)O\(\): H–O–H with two lone pairs on oxygen

Each line is a bonding pair; the dots on oxygen are lone pairs not involved in bonding.

\(\)CO\(_2\): O=C=O with two lone pairs on each oxygen

Double lines show double bonds (four electrons shared between atoms).

\(\)NH\(_3\): N bonded to three H atoms, one lone pair on nitrogen

The lone pair on nitrogen affects the molecule's pyramidal shape and reactivity.

Common mistakes

Drawing \(\)H\(_2\)O\(\) with no lone pairs on oxygen → Oxygen has two lone pairs in \(\)H\(_2\)O\(\) Oxygen has six valence electrons; two are used in bonds, so four remain as lone pairs.
Forgetting to count all valence electrons before placing them → Sum all valence electrons first, then distribute as bonds and lone pairs Every valence electron must appear in the structure as either a bond or a lone pair.
Giving hydrogen more than two electrons (one bond) → Hydrogen can only form one single bond Hydrogen achieves a full shell with two electrons, so it never has lone pairs or multiple bonds.

Where you'll use it next

You'll use Lewis structures to predict molecular geometry with VSEPR theory, understand polarity and intermolecular forces, and explain reaction mechanisms in organic chemistry.

Found in 1 StudyPug lesson

Lewis Structures: Visualizing Chemical Bonds and Electron Arrangements

Chemistry 11

Discover the power of Lewis structures in chemistry. Learn to draw diagrams for molecules like H2O and NaCl, predict molecular geometry, and understand bonding patterns. Perfect for students and aspiring chemists!

11th Grade11th