1. If you have two identical size containers,
but one is filled with zinc that has a
density of 7.14 g/cm3 and one is filled
with copper that is 8.96 g/cm3, which one
would feel heavier?
A) ZINC
B) COPPER
1. If you have two identical size containers,
but one is filled with zinc that has a
density of 7.14 g/cm3 and one is filled
with copper that is 8.96 g/cm3, which one
would feel heavier?
B) COPPER
2. Why did the pre 1982 pennies have a
higher density than the post 1982
pennies?
A. There were more pennies in one sample
than the other
B. The pre 1982 pennies were made with
copper, while the 1982 pennies must be
made with something else
2. Why did the pre 1982 pennies have a
higher density than the post 1982
pennies?
B. The pre 1982 pennies were
made with copper, while the
1982 pennies must be made
with something else
3. What do you think would float in oil that
has a density of 0.91 g/mL?
A. Plastic bead with a density of .67 g/mL
B. Copper penny 7.25 g/mL
3. What do you think would float in oil that
has a density of 0.91 g/mL?
A.Plastic bead with a density
of .67 g/mL
Cerium
Cesium
Chromium
Cobalt
Copper
Dysprosium
Erbium
Uranium
Ce
Cs
Cr
Co
Cu
Dy
Er
U
6.77
1.93
7.15
8.86
8.96
8.55
9.07
19.1
Vanadium
Ytterbium
Yttrium
Zinc
Zirconium
V
Yb
Y
Zn
Zr
6.0
6.90
4.47
7.14
6.52
DENSITY
Things that are more
dense than their
surroundings will sink.
What is more dense?



It has mass and takes up space
Everything around us is matter
We have learned that we can classify
matter based on it’s composition
How does it look? Color, sheen, texture
What does it weigh?
How does it react?
Can it poison us?
Physical Properties
Chemical Properties


Definition: can be observed without
altering the chemical composition of a
substance
Examples: color, texture,
malleability, solubility, mass,
volume, density, melting and
boiling points


Maleability-
Able to be pounded out and
shaped

Solubility - The ability
of something to
dissolve
Density How much mass per unit (volume)
of matter


D=m/v
Color?
 Texture?
 Malleability?
 Mass?
 Solubility?

Physical properties can be
described as being intensive
or extensive.
• Dependent
on
size
• volume, mass, and
length – this
property changes
when you change
the sample size
• do
not change with the sample
size
• can be useful in identifying a
substance

color, density, viscosity (how thick/thin or
slippery), temperature, solubility, and states of
matter.
• EXAMPLE:
DENSITY
• What if you had a 1 kg Chocolate
Bar (BIG) with a density of 5g/ml
• Mass-
1000g
• Volume- 200mL
• D=m/v
• D= 1000/200
• D=5g/mL
• EXAMPLE:
DENSITY
• If I cut it in 2, each half would
now be 100mL in size (volume)
and 500g in mass
• D=m/v
• D=500/100
• D=5g/mL
• same density!!
the characteristics
(ability) of a substance to
combine with or change into
other
 Definition:

Toxicity, reactivity, flammability,
radioactivity

Toxicity?


Reactivity


Very low
Flammability?


Non- toxic
Non-flammable
Radioactivity?

I sure hope not!!
Kids play with this
stuff!
 The
boiling point of
a certain alcohol is
75 degrees Celsius
Physical
 Copper
forms green
copper carbonate
when in contact
with moist air
Chemical
Table
salt
dissolves in
water
Physical
 Copper
is a good
conductor of heat
and electricity
Physical
 Magnesium
burns
brightly when
ignited
Chemical
 Iron
is more dense than
aluminum
Physical
Want to see something on our
period table that is pretty dense?
And pretty toxic?
Solubility


Solubility - The ability of
something to dissolve
In a solution, the solute is
dissolved in the solvent.
What affects solubility?
 Temperature of the solvent


Size of solute (surface area)
Agitation of solution
(stirring/shaking)
Solubility – 3 Levels
1. Saturated
 The maximum
amount of solute that
can be dissolved at a
particular
temperature is
dissolved.
We also call this the
saturation point.
SATURATED SOLUTION
What would happen if you
reached the saturation point
of sugar in your iced tea that
had a temperature of 25
degrees C, but you kept
adding more sugar?
1. What would happen to the
sugar when you added
more?
2. What could you do to get it
to dissolve?
Solubility
2. Unsaturated
 More solute can be dissolved.
It has not
reached the
saturation
point
UUUGGGHHHH!!
Jake, you made
this Kool-Aid SO
WEAK it sucks!
Add more solute!!
Solubility
3. Supersaturated
 More solute -than should be dissolved at
that temperature -is dissolved.
 Precipitate – stuff that “falls out” and can„t
dissolve
Usually achieved when we cool something
down after making it saturated at a higher
temp…like rock candy..
MMMNNN….
Sweet luscious
rock candy!!
This shows
the
solubility
curves for
different
substances
The NaNO3
is more
soluble in
400 water
than KNO3
These are
LINES OF
SATURATION
for different
substances
How much
NaNO3 can
be
dissolved
in water
that is
30oC?
What
temperature
must water
be warmed
to in order
to dissolve
80g of
KNO3?
30g of KCl is
dissolved in
water warmed
to 80oC. Is the
solution
saturated,
unsaturated, or
supersaturated
?
100g of NH4Cl is dissolved in water
warmed to 50oC. Is the solution saturated,
unsaturated, or supersaturated?
FOLD A PIECE OF NOTEBOOK PAPER INTO 2
COLUMNS AND WRITE THESE TITLES
Physical Changes
Chemical Changes
Matter can change
Examples: Freeze, cut, burn, etc.
2 types of changes
1. Physical changes
2. Chemical changes
PHYSICAL CHANGES vs.
CHEMICAL CHANGES
What’s the Difference?.......
Physical Changes
Definition: when the state or form of matter
is changed physically or mechanically (but
it is still the same stuff) –no new substances
Examples: breaking, cutting, freezing, melting, etc.
CLUE OF A
PHYSICAL
CHANGE…”Can it
be turned back into
how it started?” Yes
Physical Changes
Examples: breaking, cutting, freezing,
melting, etc.
Physical Changes
Examples: breaking, cutting, freezing,
melting, etc.
Chemical Change
Definition: a change on the molecular level
(reaction) and produces a new substance.
A chemical change always involves a chemical
reaction
Where is the Evidence???
Evidence of chemical change:
color change, gas production, and release
of heat, light, new smell, or sound.
Examples: Burning (combustion), rusting,
tarnishing and fermenting
Where is the Evidence???
Examples: Burning (combustion), rusting,
tarnishing and fermenting
Let’s Practice
Hold up your card and show P for a
Physical Change or C for a Chemical
Change
A chemical change always involves a
chemical reaction
ice melting
burning a chemistry book
melting iron
frying an egg
fireworks exploding in the sky
turning wood into a baseball bat
baking a cake
sharpening a pencil
sulfuric acid added to sugar
http://www.youtube.com/watch?v=nqDHwd9r
G0s
carving a watermelon into a creepy looking
face
pouring liquid nitrogen into a bowl and
watching it vaporize
Ticket out the Door
1. A lot of medicines are kept in dark brown
bottles (not clear) to protect them. What
kind of change (do you think) is being
prevented by keeping the sunlight out?
Physical or Chemical
2. If you let saltwater evaporate, the salt is
left behind. This is a method of making
drinking water from sea-water called
desalination. Is this a physical or chemical
change?