Colloid Colloid In chemistry, a colloid is a mixture in which one substance of microscopically dispersed insoluble particles is suspended throughout another substance. Sometimes the dispersed substance alone is called the colloid; the term colloidal suspension refers unambiguously to the overall mixture (although a narrower sense of the word "suspension" is distinguished from colloids by larger particle size). Unlike a solution, whose solute and solvent constitute only one phase, a colloid has a dispersed phase (the suspended particles) and a continuous phase (the medium of suspension). To qualify as a colloid, the mixture must be one that does not settle or
Solidus (chemistry) Solidus (chemistry) In chemistry, materials science, and physics, the solidus is the locus of temperatures (a curve on a phase diagram) below which a given substance is completely solid (crystallized). The solidus is applied, among other materials, to metal alloys, ceramics, and natural rocks and minerals. The solidus quantifies the temperature at which melting of a substance "begins", but the substance is not necessarily melted "completely", i.e., the solidus is not necessarily a melting point. For this distinction, the solidus may be contrasted to the liquidus. The solidus is always less than or equal to the liquidus, but they need