www.boeing.com/Features/2012/10/bds_champ_10_22_12.html Physical Science Class Notes Ch 2. Classification of Matter/Properties of Matter/Phases of Matter Matter: Anything that has mass and volume. Properties of Matter Physical Properties: Color, Shape, Size, Mass, Weight, Volume, and Density Chemical Properties: Flammability, Oxidation, Reactivity Substances vs. Mixtures Substances: Matter that has a uniform and definite composition (i.e. every sample of a substance has the same composition). Mixtures: Matter that consists of two or more substances that are mixed together, but are not chemically combined. Ex’s: Sand in water, Gravel in water, Cereal, Oil and vinegar, etc. *Mixtures can be separated manually or by using filters, magnets, evaporation etc. Try separating gold in a pan also containing sand. Mixture Types (4): 1. Heterogeneous: A mixture that does not appear to be the same throughout. Particles are visible and easily separated Ex: Oil/Vinegar, Orange juice and Sand/water 2. Homogeneous: A mixture that appears to be the same throughout. Particles are not easily recognized Ex: Milk, Sugar-water, Salt-water 3. Colloids: Homogeneous mixtures with particles that are not dissolved. Ex: Storm-water from construction sites, smoke and paint. 4. Solutions: A mixture in which the particles are dissolved. *Can be solid, liquid or gas Ex: Tea, Saltwater, Sugar-Water Related Terms: Solute: A substance that is dissolved in a solution. * Can be solid liquid or gas. Solvent: A substance in a solution that dissolves another substance. Solubility: A measure of how much solute can be dissolved in a given amount of solution, under certain conditions. Soluble: Able to be dissolved. Insoluble: Unable to be dissolved. Alloy: A metal solution. Ex: Brass: A mixture of copper and zinc. Suspension: A heterogeneous mixture that separates into layers over time. Pure Substances: Elements and Compounds Elements: The simplest form of a pure substance. Made up of Atoms: The basic building block of matter. Ex: Iron (Fe), Lead (Pb), Hydrogen (H), Carbon (C) Molecule: A neutral combination of atoms that are covalently bonded together. Compounds: Pure substances made up of molecules that contain more than one kind of atom. *Compounds can be broken down into simpler substances. Ex: Water is a compound made up of 2 atoms of hydrogen that are chemically bonded to 1 atom of oxygen. Chemical Reactions Flammability: Ability to burn in the presence of oxygen. Reactivity: Ability to combine chemically with another substance. http://www.youtube.com/watch?v=0QaaUw7B_js http://www.youtube.com/watch?v=92Mfric7JUc Recognizing Chemical Changes Physical: A change of size, shape or phase. Chemical: Forms a new substance. Color Change Ex: Steel turns orange and copper turns green Color Change Indicators: Iodine Production of a Gas Ex: Baking soda/vinegar, chlorine/ammonia = Toxic: poisonous or harmful to humans. Formation of a Precipitate Ex: Milk/Acid makes cheese. Temperatures Change Ex: Batteries getting warm Law of Conservation of Mass: Matter cannot be created or destroyed. It can only change forms. The mass of the products is always equal to the mass of the reactants. During any physical or chemical change, mass is conserved. Ch 3 States/Phases of Matter Kinetic (Greek=to move) Theory: All particles of matter are in constant motion. Phase Characteristics Solid: Definite shape and volume. Liquid: Definite volume but variable shape. Gas: Variable volume and variable shape. Plasma: High energy gas abundant within stars that must be contained using magnetic fields. Bose-Einstein Condensate (BEC): Matter cooled to near absolute zero (0 K) with atoms behaving as single particles. State/Phase Changes *Changes in phase are caused by an increase or decrease in energy. Related Terms: Melting: Change of a solid to a liquid Melting Point: The temperature at which a solid changes to a liquid. Freezing Point: The temperature at which a liquid changes to a solid. Vaporization: Change in a substance from liquid to gas. Evaporation: Vaporization that takes place at the liquids surface. Boiling: Process by which the particles inside a liquid as well as on the surface of a liquid change to gas. Boiling Point: Temperature at which a liquid boils. * The lower the air pressure, the easier it is for the particles to travel up through the liquid and leave as a gas. *As air pressure decreases, such as with increased altitude, the boiling point decreases. Condensation: Change of a gas to the liquid phase. Sublimation: When the particles on the surface of a solid change directly to the gas phase. Ex: Dry ice Deposition: When a gas goes directly to the solid phase without forming a liquid. Behavior of Gases Boyle’s Law: The volume of a fixed amount of gas varies inversely with the pressure of the gas (i.e. as one increases, the other decreases). Ex: If you push down on the handle of a bicycle pump, you decrease the volume of the cylinder, and you increase the pressure of the gas inside. P1V1= P2V2 Charles’s Law: The pressure and/or volume of a fixed amount of gas varies directly with the temperature. Ex: Basketballs get flat when they are cold. V1 = V2 T1 T2 *Together, Boyle’s Law and Charles’ Law are referred to as the Gas Laws and they describe the behavior of gas with regard to: volume, temperature, and pressure. P1V1 T1 = P2V2 T2 Discuss phet simulator for phases of mater Heat and Phase Changes *Energy is either absorbed or released during phase changes. Heat of Vaporization: The amount of energy that must be absorbed when a substance changes from a liquid to a gas. Ex: Boiling water on a stove at different altitudes Heat of Fusion: The amount of energy that must be absorbed when a substance changes from liquid to a solid. Ex: Using ice to protect crops. Exothermic: Phase changes and chemical reactions that involve a release of energy. Endothermic: Phase changes and chemical reactions that involve absorption of energy.