Britannica Sources used in this answer

How does activated charcoal absorb gases and coloring materials?

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

A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — carbon group element Modern version of the periodic table of the elements (printable).

Activated charcoal, a form of carbon, effectively removes gases and coloring materials through a process called adsorption.

Unlike absorption, which involves a substance penetrating the interior of a material, adsorption is the collection of molecules onto the surface of a solid adsorbent. Activated charcoal is manufactured using special techniques to create a highly porous structure, resulting in an immense internal surface area—often ranging from 300 to 2,000 square metres per gram.1

This vast surface area provides extensive space for molecules of gases or dissolved impurities to be trapped. The process relies on physical or chemical forces of attraction between the charcoal surface and the adsorbate molecules. Because of this high porosity and surface area, activated charcoal is widely used for purifying liquids, such as water and sugar, and for removing toxic compounds from air in gas masks.213