In which state is alginate when it is in liquid form?

Alginate is in the sol state when it is in liquid form. In this state, alginate is a colloidal solution that has the properties of a fluid, allowing it to flow and be easily manipulated. The term "sol" refers to a suspension of solid particles within a liquid, which is exactly how alginate behaves before it gells.

Once a setting reaction occurs, generally initiated by the addition of a calcium ion, the alginate transitions to a gel state, where it becomes more rigid and firm. This property is essential in dentistry for making impressions because it allows the material to capture fine details of the dental structures.

The other states mentioned refer to different forms that alginate can take, such as its powder state prior to mixing or its solid or gel state after it has set. Understanding these different states is important in dental applications, especially when working with impression materials.