gaseous diffusion

chemistry

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 29, 2026

Quick Summary

Gaseous diffusion is the process where gases spread through a porous barrier. The rate of diffusion is directly related to the weight of the gas molecules; lighter molecules diffuse faster than heavier ones. This principle is utilized in separating isotopes, such as enriching uranium for nuclear applications.12

In dilute gases, diffusion is a statistical phenomenon driven by the constant motion of molecules. While individual molecules travel vast distances between collisions, their random paths result in a slow net movement, making diffusion a gradual process. This property is quantified by the diffusion coefficient, measured in square meters per second, and is influenced by temperature and pressure.34

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

4 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

nuclear reactor
Enrichment
…a large scale; these are gaseous diffusion and gas centrifuging. In gaseous diffusion, natural uranium in the form of uranium hexafluoride gas (UF₆), a product of chemical conversion, is encouraged (through a mechanical process) to seep through a porous barrier. The molecules of ²³⁵UF₆ penetrate the barrier slightly faster than…
Read More
…a large scale; these are gaseous diffusion and gas centrifuging. In gaseous diffusion, natural uranium in the form of uranium hexafluoride gas (UF₆), a product of chemical conversion, is encouraged (through a mechanical process) to seep through a porous barrier. The molecules of ²³⁵UF₆ penetrate the barrier slightly faster than…
Read More

John R. Dunning
…at Columbia that developed the gaseous-diffusion method of separating uranium-235 from the more abundant uranium-238 isotope. Gaseous diffusion is still the principal method for obtaining uranium-235. Dunning became a full professor of physics at Columbia in 1946 and headed its engineering faculty from 1950 to 1969.
Read More
…at Columbia that developed the gaseous-diffusion method of separating uranium-235 from the more abundant uranium-238 isotope. Gaseous diffusion is still the principal method for obtaining uranium-235. Dunning became a full professor of physics at Columbia in 1946 and headed its engineering faculty from 1950 to 1969.
Read More