Properties of Matter

Properties of MatterChapter 15 Section 2Classify these PROPERTIES as physical or chemical. If you arent sure, guess!Color______________________________Flammability ______________________________ Odor ______________________________Shape ______________________________ Taste ______________________________ Density ______________________________ Melting Point ______________________________Tendency to Rust______________________________ Reacts with light ______________________________Boiling Point ______________________________Volume ______________________________Malleable ______________________________Mass ______________________________Magnetism ______________________________Ductile ______________________________Ability to dissolve______________________________

Physical PropertiesA characteristic of a material that you can observe without changing the identity of the substance that makes up the materialCan be observed with your senses and can be determined without destroying the object*If a new smell is produced as the result of a change, it would not be considered a physical property

Physical PropertiesPhysical Properties can be related to:AppearanceWhat color is the item?What shape is the item?What is the items phase of matter?

BehaviorDoes it attract a magnet? i.e. ironCan it be pulled into wires (ductile)? i.e. copperCan it be hammered into sheets (malleable)? i.e. goldAt what temperature does it boil (boiling point)?Is the substance soluble (does it dissolve)?

Physical PropertiesPhysical properties can be used to separate substances in a mixture

How would you separate a mixture of iron, sand, and salt using physical properties?http://www.youtube.com/watch?v=Rc9o2tbOxxY

Chemical PropertiesA characteristic of a material that indicates whether it can undergo a certain chemical changeThe result of the chemical change would be the production of a new substance

Some examples:tendency of something to burn (flammability) i.e. lighter fluid, paint thinnertendency of something to react with light i.e. medicines that come in dark bottles like hydrogen peroxide (H2O2)

Try this Again! Classify these PROPERTIES as physical or chemical. If you arent sure, guess!Color______________________________Flammability ______________________________ Odor ______________________________Shape ______________________________ Taste ______________________________ Density ______________________________ Melting Point ______________________________Tendency to Rust______________________________ Mass ______________________________Boiling Point ______________________________Volume ______________________________Malleable ______________________________Reacts with light______________________________Magnetism ______________________________Ductile ______________________________Ability to dissolve______________________________

PhysicalChemicalPhysicalPhysicalPhysicalPhysicalPhysicalChemicalPhysicalPhysicalPhysicalPhysicalChemicalPhysicalPhysicalPhysicalClassify these CHANGES as physical or chemical. If you arent sure, guess!Evaporating water __________________________Rust on an iron nail __________________________Baking cookies __________________________Dissolving salt in water __________________________Hammering Aluminum into a sheet _________________Cooking scrambled eggs _________________________Burning a marshmallow __________________________Melting an M&M in your mouth ____________________Alka seltzer in water __________________________Raising bread dough __________________________Cutting an apple __________________________

Physical ChangeA change in the size, shape, state of matter, etc. that does not change the identity of a substance

A phase change is a physical change even though energy may be removed or added to the substance

In the new state of mater, the substance is still made of the same components, the atoms just have more or less energy (phase changes are the only physical changes that have energy changes)i.e. if liquid water evaporates, it becomes water vapor if water vapor condenses, it becomes liquid waterPhase ChangesSOLIDLIQUIDGASMeltingLiquefyingEvaporatingBoilingDepositionSublimationFreezing,Hardening, SolidifyingCondensing10DistillationDistillation is a process that takes advantage of physical properties and physical changes to separate mixturesIf two substances have different boiling points (temperature at which they boil), they can be separated. The mixture is heated slowly until it begins to boil.The vapors of the liquid with the lowest boiling point form first and are condensed and collected. If the other substance also needs to be collected, then the temperature is increased until the second liquid boils, condenses, and is collected Distillation Set-Up

Chemical ChangeThe change of one substance into a new substance (chemical reaction)A chemical change alters the original chemical make-up of the substanceEnergy changes and physical changes always accompany chemical changes

Indications of a Chemical ReactionHow can you tell if a chemical change has taken place?ENERGY Evolution of heat, light, and/or sound (sometimes heat can be absorbed too)

GAS A gas is produced, bubbles (effervescence)

PRECIPITATE When solid particles form from 2 liquids

COLOR Unexpected Color change (i.e. clear liquid + clear liquid purple liquid)

14Objective:To state four observations that are evidence for a chemical reaction.

Photo of precipitate: http://www.geocities.com/chem_reactions/Images/Precipitate.jpgTry this Again! Classify these CHANGES as physical or chemical. If you arent sure, guess!Evaporating water __________________________Rust on an iron nail __________________________Baking cookies __________________________Dissolving salt in water __________________________Hammering Aluminum into a sheet _________________Cooking scrambled eggs _________________________Burning a marshmallow __________________________Melting an M&M in your mouth ____________________Alka seltzer in water __________________________Raising bread dough __________________________Cutting an apple __________________________

PhysicalChemicalChemicalPhysicalPhysicalChemicalChemicalPhysicalChemicalChemicalPhysicalLaw of Conservation of MassMatter is neither created nor destroyed during a chemical change (reaction)

The mass of the substances present before the chemical change equals the mass of the substances that remain after the change

ExampleIs burning wood a physical or chemical change?

After a log burns, only ashes remain. Where do you think the rest of the mass went?Chemical change - CombustionSome mass left as solid particles in the smoke, some mass left as gas (CO2)Example of Chemical ChangesWhat color was the Statue of Liberty when it was dedicated in 1886?NOT green!The Statue of Liberty is made of copperThe copper at the surface has undergone a chemical change as the result of exposure to air and water. She is now covered in patina which is green!