many commercial glass products such as containers are made of soda-lime glass, and therefore have a substantial percentage of sodium ions in their internal structure. since sodium is an alkali element, its selective removal from the surface results in a dealkalized surface. a classic example of dealkalization is the treatment of glass containers, where a special process is used to create a dealkalized inside surface that is more resistant to interactions with liquid products put inside the container. however, the term dealkalization may also be generally applied to any process where a glass surface forms a thin surface layer that is depleted of alkali ions relative to the bulk. a common example is the initial stages of glass corrosion or weathering, where alkali ions are leached from the surface region by interactions with water, forming a dealkalized surface layer.