What is the definition of solubility?

Solubility is defined as the ability of a substance to dissolve in a solvent, forming a homogeneous solution at a specified temperature and pressure. This process is essential in various fields, including chemistry and beauty therapy, as it determines how well active ingredients can be incorporated into products like creams and serums. The concept of solubility is crucial for formulating effective skincare products, where the therapeutic agents need to be soluble to be effective.

In this context, the other options do not accurately define solubility. The ability to conduct heat pertains to thermal conductivity, which is unrelated to the dissolution process. The maximum temperature a substance can reach is related to thermal properties, not its solubility. The rate at which a substance evaporates deals with vaporization, which is again a different concept separate from how a substance dissolves in a solvent. Understanding solubility helps ensure that beauty products deliver their intended benefits effectively.