Colloids typically fall within which particle size range?

Colloids are defined by their particle size, which typically ranges from 1 nanometer to 1 micron. Therefore, the option indicating a size range of 0.001-1 microns accurately fits the definition of colloidal particles. Colloids consist of small particles that remain suspended in a medium due to their size, which prevents them from settling out like larger particles would. This characteristic is essential in various water treatment processes, as colloids can influence the clarity and quality of water.

In contrast, the other options either fall outside of this accepted colloidal range or include particles that would be considered too large. Understanding the particle size distribution associated with colloids is crucial for effective water treatment management, especially when dealing with coagulation, flocculation, and filtration processes.