In this lesson by Mrs. Tell, students learned about the concepts of solubility, focusing on distinguishing between soluble and insoluble substances. Examples included dissolving common solutes like sodium chloride (salt) and sugar in water, which acts as a solvent, and examining the solubility of coffee, both instant and non-instant forms. The lesson also demonstrated the insolubility of silica (silicon dioxide), using sand as an example of an insoluble compound, emphasizing how stirring can speed up the dissolving process.