About Mixtures : Matter that consists of two or more substances that are not chemically combined is called a mixture. Mixtures are classified according to how well they are mixed.
Heterogeneous mixtures are the least mixed. The particles of this mixture are large enough to be seen and to separate. The particles will settle out on standing. An example of this mixture would be sand and water.
Homogeneous mixtures are well mixed. The particles that make up this mixture are very small and do not settle out when allowed to stand. Solutions and colloids are examples of homogeneous mixtures.