Mixtures and Solutions

     The eigth grade science class is curenttly learning about mixtures and solutions. A substance is matter that is always made up of the same combination of atoms. There are two types of substances; elements and compounds.  An element is made up of only one type of atom such as Nitrogen (N).  A compound is matter made of atoms of two or more elements chemically bonded together, such as water (H₂O).  A mixture is two or more substances that are physically blended, but are not chemically blended together.  A good example of a mixture is air.  It contains seventy eight percent nitrogen, twenty one percent of oxygen, and one percent of other substances.  There are two types of mixtures; heterogeneous and homogeneous.  A heterogeneous mixture is a mixture in which substances are not evenly mixed, such as granite.  A homogeneous mixture is a mixture in which two or more substances are evenly mixed on an atomic level, but not blended together.  The individual atoms or compounds of each substance are mixed.  Another name for a homogeneous mixture is a solution.  In a solution there is a solvent, and a solute.  A solute is the substance that exists in the greatest quantity in a solution.  All other substances in a solution are solutes.

                                                               Heterogenous Mixture

Emma V.