Mixtures and Solutions

Physical Science - Middle School

Mixtures & Solutions Mixtures A mixture is the physical combination of two or more substances. Mixtures can be made of compounds and elements. The substances in a mixture are not chemically combined, and they are not found in an exact ratio. The ingredients keep their individual properties and can be separated. This nut mixture is called a heterogeneous mixture, because you can see the individual substances. In a homogeneous mixture, like paint, you cannot see the individual parts that make up the mixture. heterogeneous mixture homogeneous mixture heterogeneous mixture homogeneous mixture solute solvent water salt solute (salt) solvent (water) Colloids are a type of mixture in which particles are too small to see, but they are large enough to scatter light and be filtered. Milk, gelatin, whipped cream and many of the foods we eat are considered colloids. Suspensions & Colloids If the particles that are dispersed throughout a mixture are large enough to be seen and they scatter or block light, then the mixture is called a suspension. Eventually these particles will separate and settle out. For example, if you mix sand in a beaker of water, and then let it sit for a while, the sand particles will settle on the bottom of the container. suspension colloid Separating Mixtures Substances in a mixture are not chemically bonded together and therefore can be separated using a variety of techniques. Magnets can be used to separate a mixture of nails that are made of iron and aluminum. Some mixtures made up of liquids and solids can be separated using filters. Distillation is a process used to separate substances that have different boiling points, like water and salt. A centrifuge is a machine that spins mixtures at high speeds. It can be used to separate substances by their densities. Star t Stop 0.0 0 magnet centrifuge filter distillation Solutions A solution looks like a single substance, but it is actually a homogeneous mixture made up of two or more evenly distributed substances. For example, when salt is mixed with water, the salt particles dissolve, or mix evenly, with the water particles. The salt, which is the substance that dissolved, is called the solute. The water, which caused the salt to dissolve, is called the solvent. Solutions can be liquids like anti-freeze, or gases like the air we breathe, or even solids, like brass. The concentration of a solution is the amount of solute in a given amount of solvent. Concentrations are often measured in grams per milliliter. A concentrated solution has more solute in it than a dilute solution. © Copyright NewPath Learning. All Rights Reserved. 94-4827 Visit www.newpathlearning.com for Online Learning Resources. heterogeneous mixture homogeneous mixture concentrated dilute sand
Mixtures & Solutions Denition Element Compound Mixture Solution Suspension Colloid Examples © Copyright NewPath Learning. All Rights Reserved. 94-4827 Visit www.newpathlearning.com for Online Learning Resources. Pause and Review Fill out the table below with definitions and examples. ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________