Which characteristic is essential for a material to be termed 'soluble'?

A material is termed 'soluble' primarily when it can dissolve completely in a chosen liquid, forming a homogeneous solution. This means that when the material is added to the solvent, it breaks down into its individual particles and disperses evenly throughout the liquid, which allows for the solution to appear clear and uniform.

The significance of this property is crucial in many aquatic applications, such as the effectiveness of herbicides or nutrients in water bodies, where the solubility of a compound can greatly influence its bioavailability and efficacy against targeted organisms. Understanding the nature of solubility helps professionals apply chemicals correctly and predict how they will behave in aquatic ecosystems.

The other options do not accurately define solubility; for example, forming a sediment indicates that the material is not fully dissolved, while mixing with solids does not pertain to the characteristic of a liquid solution. Similarly, being in a solid form does not imply solubility, as many solids are insoluble in various liquids.