PROPERTIES OF MATTERChapter 15 Section 2

CLASSIFY THESE PROPERTIES AS PHYSICAL OR CHEMICAL. IF YOU AREN’T 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 PROPERTIES

A characteristic of a material that you can observe without changing the identity of the substance that makes up the material

PHYSICAL PROPERTIESPhysical Properties can be related to:

AppearanceWhat color is the item?What shape is the item?What is the item’s 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)?

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 change

The 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 thinner

tendency 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 AREN’T 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 ______________________________

PhysicalChemicalChemicalPhysicalChemicalPhysicalPhysicalChemicalPhysicalPhysicalPhysicalPhysicalChemicalPhysicalPhysicalPhysical

CLASSIFY THESE CHANGES AS PHYSICAL OR CHEMICAL. IF YOU AREN’T 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 CHANGE A 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 energyi.e. if liquid water evaporates, it becomes water vapor

if water vapor condenses, it becomes liquid water

PHASE CHANGESSOLID

LIQUIDGAS

Meltin

g

Liquefyin

g

EvaporationBoiling

Deposi

tio

n

Sublim

atio

n

Freezin

g,

Hard

enin

g,

Solid

ifying

Condensing

DISTILLATION Distillation is a process that takes

advantage of physical properties and physical changes to separate mixtures

• If 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 CHANGE

The change of one substance into a new substance (chemical reaction)A chemical change alters the

original chemical make-up of the substance

INDICATIONS OF A CHEMICAL REACTION

How 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)

TRY THIS AGAIN! CLASSIFY THESE CHANGES AS PHYSICAL OR CHEMICAL. IF YOU AREN’T 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

Chemical

Chemical

Physical

Physical

Chemical

Chemical

Physical

Chemical

Chemical

Physical

LAW OF CONSERVATION OF MASS Matter 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 - Combustion

Some 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!