Describing Matter Matter- anything that has mass and takes up space Unit 2.4

Element vs. Compound Element- a substance in which all atoms are alike The periodic table has the complete list of elements. Compound- substance in which the atoms of two or more different elements are combined in fixed proportions Ex. H2O, CH4

Pure Substances Pure Substance-cannot be broken down into simpler components and still maintain the properties it had originally Either an element or a compound

Elements vs Compounds C Element S8 Element H2O Compound Si2 Element All of the above are pure substances!

Describing Matter Mixture- made up of two or more pure substances which can be separated by physical means Homogenous- contains two or more pure substances blended evenly throughout Heterogeneous- contains two or more pure substances that can be distinguished from each other Homogenized Milk Heterogeneous (Non-Homogenized) Milk

Types of Homogeneous Mixtures Miscible: describes a homogeneous mixture in which two or more liquids that can mix with each other Ex. Orange-Pineapple juice Solution- homogeneous mixture containing a solute (typically sugar or salt) dissolved in a solvent (typically water) Ex. Gatorade 3 Types of Solutions Unsaturated solution: a solution capable of dissolving more solute Saturated solution: a solution that cannot dissolve any more solute Supersaturated solution: a solution that has more solute dissolved in it than it can normally hold and the extra solute can easily crystallize or precipitate out Video

Types of Heterogeneous Mixtures Immiscible: describes a heterogeneous mixture in which two or more liquids that don’t mix with each other Suspension: heterogeneous mixture containing a liquid in which visible particles settle out over time Ex. dirty water, orange juice with pulp (that’s why you shake it) Colloid: heterogeneous mixture with large particles that never settle Ex. fog, smoke, ink, glue A test you can run to see if it’s a colloid is to pass a beam of light through the mixture, if the light is visible, it is a colloid and this is called the Tyndall Effect

Tyndall Effect

Compare and contrast mixtures and compounds How can you tell the difference between mixture and compound? Mixture can be separated physically and keep its properties Ex. Salt Water Compound can only be separated chemically and does NOT keep its properties Ex. Water (H2O), by separating the water, you get hydrogen and oxygen gas which are extremely flammable together