Section1
A. Physical12ro12erty-anycharacteristicof matter that canbe observed
without changingthe identity of the material
1. Physical properties include color) shape)smell) taste)~)
2. Density-amount
volume) and density.
of mass in a given volume; a golf ball would have greater density than a
table-tennisball; the formula for densityis: density (g/cm3)=mass(g)/volume (cm3)
3. Densitycanbe usedto identin unknown substances;
a personcould determinethe composition of a pieceof jewelry by comparingits densitywith the densityof a known substance
suchassilver or gold.
4. Stateof matter-whether a substanceis a solid, liquid, or a gasat a particular temperature
and pressure
5. Somephysicalpropertiesaresize-del2endent
(length,width, height,volume,and mass)
while othersare size-indel2endent
(density,color,state).
B. Matter canbe classifiedasan acid or a base.
1.
~
tend to havea sharpsmelland a sour taste(but you should NEVERtasteanythingin
a laboratory) with a pH between0 and 7; citrus fruits contain acids.
U
.£
,,;
Q)
2. ~
feelslipperyand tastebitter and havea pH of between7 and 14;a bar of soapis a base.
3. Water,with a pH of exactlyz,is neither an acid nor a base;it is neutral.
DISCUSSION
QUESTION:
What are some physical properties? Color, shape,smell, taste,mass,volume, density,state,and
acid/baseclassification
Section2
".:
~
E
u0
~
~
'-'
OJ
~
Q)
~
'0
to
0
"iij
">
13
ro
:of
A. Chemical{2ro{2erty-characteristicof somethingthat allowsit to changeto somethingnew
1. Chemicalpropertiesinclude flammability,toxicity, and reactivit}: with oxygen;when a halfeatenappleturns brown in the air, a chemicalreactionwith oxygenhasoccurred.
2. Silverand gold havelower reactivitythan many other metals,which helpsmakethem good
choicesfor jewelry.
T2 Properties
andChanaes
of Matter
~
'-'
OJ
~
..,.
0
OJ
to
Q)
a
@
~
~
0
0
3. Chlorine compoundschangethe chemicalpropertiesof 12QQl water, making it more acidic
in order to eliminate algae,bacteria, and insects.
a. Standingwater,without addedchlorine, canbecomea breedingground for insects,such
asmosQuitoes.
c. The more acidic chlorinatedpool water can alsoirritate the skin and ~
B. Acidsand baseshavechemicalpropertiesthat makethem both ~
of swimmers.
and harmful.
a. Tomato sauceis acidic enough to reactwith aluminum foil, but will not harm human beings.
b. Acid rain can damage plant and animal tissues.
c. Sulphuric acid is useful in industry, but causesburns on skin.
3.
~-compounds
made of a metal and nonmetal and that are formed when acids and
basesreact
a. Thhk salt can be formed from a base sodium hydroxide and hydrochloric acid.
b. Calcium carbonate,or ~,
and ammonium chloride,which is usedin batteries,are
oj
Eo
,,;
OJ
'c
co
Co
E
0
u
:r
~
(!)
OJ
~
.,
;;
'0
c
0
Ow
os:
'0
CO
~
~
(!)
OJ
~
..,.
0
OJ
C
.,
15
usefulsalts.
DISCUSSIONQUESTION:
What are three chemical properties? Flammability, toxicity, and reactivity with oxygen
Section3
A. Physicalchange-any changein size,shape,form, or statewherethe identity of the matter
staysthe same
1. Cutting a watermeloninto slicesis an exampleof a l2h~sicalchange.
2. Changeof ~
a. Solid to ~
is a common physicalchange.
(ice melting)
@
~
.~
~
0
U
b. 1iqYid to solid (water fi'eezing)
c. Liquid to ~
d. ~
(waterboiling and creatingsteam)
to liquid (watervapor condensinginto water suchaswhen dew forms)
Properties
and Changes
of Matter T3
B. Chemicalchange-one material changesinto a different materialwith different propertiesor
characteristics
1. Exarn12lesof chemical changes include digestion, photosynthesis, paint drying, and oil burning.
2. .In a chemical change,~
materials are formed that are different from the starting materials.
3. A chemicalchangecannot easilybe reversed.
4. Signsof chemicalchangesinclude the releaseor absorptionof ener~ in the form of light,
heat,or sound;formation of a gasor solid, not from a changeof state,can indicatea
chemicalchange.
C.Leaveschangingcolor indicatesa chemicalchangein nature.
1. Weathering of Earth's surface is a physical changethat takes place over long time periods.
2. Chemicalweatheringcan create~
formations.
3. Acid rain is a form of unnatural chemical change.
DISCUSSIONQUESTION:
What is the difference between a physical and a chemical change?In a physical changethe identity
of the sub$tanceremai~'5the same;in a chemical changea new substanceis formed.
.
U
Eli
Q)
I:
~
E
0
C.)
:I:
~
CO
~
'"'
~
Q)
-E
'5
c
0
'in
'>
'5
CO
:I:
~
~
CG
~
'OJ'
0
'"'
c
Q)
a
@
"tID
'~
0
C.)
14
PropertiesandChanges
of Matter