In this lesson you will learn the difference between substances and mixtures, the differences between types of mixtures, and how mixtures are separated Mixtures

Physical and chemical properties are used to classify matter into categories

Substances and Mixtures A substance has a definite makeup or composition. It also has definite chemical and physical properties Substances are either elements or compounds Carbon dioxide, table sugar, and aluminum are examples of substances

Most of the matter you see is a mixture A mixture is two or more substances mixed together The properties of the individual substances are not affected In mixtures are not chemically combined Air, garden soil, and saltwater are mixtures

Heterogeneous Mixture The substances in a heterogeneous mixture are not evenly mixed One part of the mixture may have more of one substance than another. Examples are beach sand, taco salad, and oil mixed with water

Homogenous Mixtures: Solutions A homogenous mixture is a mixture in which all of the individual substances are evenly mixed throughout; a solution All parts of a homogenous mixture have the same makeup An example is a teaspoon of sugar stirred into a cup of hot water. Even with a microscope, the sugar could not be seen in the mixture

Homogenous mixtures are also called solutions A solution is a homogenous mixture of one or more solutes dissolved in a solvent Solvent-the substance that a solute is dissolved in; usually the substance in a solution that is present in the greatest amount Solutes-A substance that is dissolved in a solvent to create a sloution

Aqueous solutions are solutions in which the solvent is water. Let’s look at a table with examples of solutions

An alloy is a solid solution containing metals Steel is a term that describes a variety of iron alloys Gold that is often used in jewelry is mixed with copper and silver to create an alloy. Pure gold is soft and can be bent easily

Separating Mixtures Mixing substances to create a mixture involves only physical changes and no chemical changes Separating a mixture only involves physical changes Suppose you wanted to separate a heterogeneous mixture of iron filings and salt. Iron fillings can be collected on a magnet, but salt cannot. You could use these physical properties to separate the mixture.