London Forces

Part of the Structure and Bonding section of Coddy's Chemistry journey. Lesson 28 of 49.

Forces between molecules are far weaker than the bonds inside them, but they decide the state at room temperature.

Moving electrons make brief dipoles that attract the next molecule: London forces. They act between all molecules, and they are the only force between non-polar molecules.

More electrons, stronger London forces: F₂ and Cl₂ are gases, Br₂ a liquid, I₂ a solid.

The four halogen molecules from fluorine to iodine, labelled gas, gas, liquid and solid at room temperature

Bigger molecules, more electrons, stronger London forces

Challenge

Chlorine, Cl₂, is a yellow-green gas. What is the strongest force between its molecules?

Try it yourself

Shape viewerDescribe the molecule Cl₂

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Structure and Bonding

2Covalent Bonds

Sharing Electrons Counting Valence Electrons Drawing Lewis Structures Double and Triple Bonds Lone Pairs Formal Charge Lewis Structures of Ions Recap - Molecule Builder

5Forces Between Molecules

London ForcesDipole-Dipole Forces Hydrogen Bonds Boiling Points Like Dissolves Like Recap - Boiling Contest

8Practice Problems

Recap - Polar Bonds Survey Recap - Pigments and Hexane Recap - Butanol and Ether Recap - Dots on an Oxide

3Shapes of Molecules

Electron Groups Linear and Trigonal Planar Tetrahedral Molecules Pyramids and Bent Molecules Bond Angles Recap - Shape Detective

6Metals and Giant Structures

Metallic Bonding Diamond and Graphite Giant Covalent Structures Four Kinds of Substance Recap - Material Match