a mixture that does not appear to be the same throughout is said to be
heterogeneous
title: Homogeneous and heterogeneous mixtures text: mixture is air. In physical chemistry and materials science this refers to substances and mixtures which are in a single phase. This is in contrast to a substance that is heterogeneous. A solution has been a special type of homogeneous mixture. Solutions are homogeneous because the ratio of solute to solvent remains the same throughout the solution even if homogenized with multiple sources, and stable because the solute will not settle out after any period of time, and it cannot be removed by a filter or by centrifuge. This type of mixture is very stable, i.e., its particles do not title: Homogeneous and heterogeneous mixtures text: constant. Homogeneous mixtures always have the same composition. Mixtures can be characterized by being separable by mechanical means e.g. heat, filtration, gravitational sorting, etc. During the sampling of heterogeneous mixtures of particles, the variance of the sampling error is generally non-zero. Gy's sampling theory quantitatively defines the heterogeneity of a particle as: where l90-8i Homogeneous and heterogeneous mixtures A homogeneous mixture is a solid, liquid, or gaseous mixture that has the same proportions of its components throughout any given sample. Conversely, a heterogeneous mixture has components whose proportions vary throughout the sample. "Homogeneous" and "heterogeneous" are not absolute terms but title: Homogeneous and heterogeneous mixtures text: Homogeneous and heterogeneous mixtures A homogeneous mixture is a solid, liquid, or gaseous mixture that has the same proportions of its components throughout any given sample. Conversely, a heterogeneous mixture has components whose proportions vary throughout the sample. "Homogeneous" and "heterogeneous" are not absolute terms but depend on context and the size of the sample. In chemistry, a homogeneous suspension of material means that when dividing the volume in half, the same amount of material is suspended in both halves of the substance; however, it might be possible to see the particles under a microscope. An example of a homogeneous title: Colloid text: 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 title: Mixture text: as its melting point, may differ from those of the components. Some mixtures can be separated into their components by using physical (mechanical or thermal) means. Azeotropes are one kind of mixture that usually pose considerable difficulties regarding the separation processes required to obtain their constituents (physical or chemical processes or, even a blend of them). Mixtures can be either homogeneous or heterogeneous. A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties. Examples of homogeneous mixtures include alloys and alcohol in water. A heterogeneous mixture