Do Now:
-Copy HW and take out Saving Fred
Monday: Finish Lab
Tuesday: Measurement Practice Ditto
Wednesday: NO HW 
Thursday: Metric Unit Practice
Friday: NO HW 
Do Now: Focused Free Write
Directions: On a clean sheet of loose-leaf
paper in your class-work section,
answer the following questions in
complete sentences
1)Why are goals important to success?
2)What are some of your goals for this
year in Science?
Do Now: Focused free Write
Directions: Take a packet from the Do
NOW desk. On a clean sheet of looseleaf paper in your class-work section
make 5 observations about our
classroom…
Unit 1: Introduction
The Nature of Science
When it comes to looking
at life, I always tend to
round up, but in Science
I know to simply follow
the rounding procedure!
P.S. My name is Elle
1.Observations:
• Are the use of the 5 senses to learn
something about the environment.
a. When you observe, you use your
____________
to take in everything
Senses
that is happening around you, paying close
attention to detail
b. Examples:
• The rock is round and smooth.
2.INFERENCE:
-Are interpretations of your
observations.
-In other words, when you infer
you form a conclusion based on
something you observed.
b. An example of an inference is:
i. The round and smooth rocks must have
been carried here by running water.
b. Examples
ii. Since the dog is wagging his tail he
must be happy.
iii. Make an inference about something
your observe in the classroom.
Prediction
• Lets looks at this picture again, what
will eventually happen to the circled
rock?
How is a prediction different than an
inference?
• An educated guess as to what will
happen in the near future based usually
on your observations and inferences.
• An example of a prediction:
i. An angular rock will eventually become
rounded if it stays in the stream.
ii. Ms. Gill will wear something stylish
tomorrow.
Closure
• Write a paragraph in your own words
comparing and contrasting the three
terms: Observation, Inference and
Prediction in your note packet
Do Now
• Observation/ Inference Worksheet on
the Do NOW desk
• Take out homework
The Nature of Science
• Working science does not simply follow a
stepwise procedure such as the scientific
method but rather limits, a level of
uncertainty, biases, reasons for its
reliability and social aspects to consider.
• Understanding of our world are constantly
evolving. There is much more to science than
simply following the scientific method, a
stepwise formula to solve problems by
testing proposed solutions.
The Nature of Science
The World Is Understandable
Scientific Knowledge Is Durable
Scientific knowledge is inherently uncertain.
Scientific Ideas Are Subject To Change
Science Demands Evidence
Science Is a Blend of Logic and Imagination
Science Explains and Predicts
Science Is Not Authoritarian
Scientists Try to Identify and Avoid Bias
There Are Generally Accepted Ethical Principles in the Conduct of
Science
• Science Cannot Provide Complete Answers to All Questions
• Science Is a Complex Social Activity
• Scientists Participate in Public Affairs Both as Specialists and as
Citizens
•
•
•
•
•
•
•
•
•
•
Lets read the blurb in
your Note packet
together!
Carolina Bay Formations
Carolina Bay Formations
Scientific Theory
• An idea explaining scientific
phenomenon supported by evidence
gathered from repeated experiments
Lets read the blurb in
your Notepacket
together!
Hypothesis
• A testable statement that describes
the solution of an experiment. Written
as “If_____________, then
_______________ because
_______________.
Lets read the blurb in
your Notepacket
together!
Scientific Method
• a stepwise formula to solve a problem by
testing a Hypothesis, it is often used in
the classroom but not always in true
science.
Do Now: Scientific Method
Worksheet on “Do Now” Desk
Copy this Weeks Homework:
Monday: Scientific Method HW ditto &
Finish Skittles Lab
Tuesday: Doing Science Worksheet
Wednesday: Finish “Saving Fred” Lab
Thursday: Graphing Worksheet
Friday: NO HOMEWORK… Enjoy your three
day weekend!
Scientific Method:
• Steps that scientist use to solve a
problem!
Scientific Method:
1. State the problem!
Example: I observe two plants
growing in my house. Why is
one taller than the other?
Scientific Method:
• 2. Gather information. (Research!)
observations, research, brainstorming
Examples:
1. Are both plants the same species?
2. Are both plants the same age?
3. Are both plants receiving the
same resources to survive?
Scientific Method
3. Develop a Hypothesis.
-based on observations and research
-Statement, NOT a question!
-can be tested
• Write your hypothesis in the space
provided!
Scientific Method
3. Develop a Hypothesis.
Ex:
If I deprive a plant of natural sunlight
then it will die because plants need
sunlight to survive.
Scientific Method:
4. Test you Hypothesis
Plan: Beginning with two identical plants
of the same starting height and species.
I will place one plant on the window sill
and another plant in the closet. I will
give each plant the same amount of
water each day (15mL) I will measure
the height every week on Fridays for
one month
Scientific Method:
5. Observe and record your data. Use
tables and notes to record observations
and measurements.
In the box provided draw a sample table
that you would use to record data
Scientific Method:
Height of Plants (CM)
Date
Plant A Window
Plant B Closet
Scientific Method:
6. Analyze & Interpret Results using
charts and graphs
Scientific Method:
7. Conclusion:
-based on observations and results
-State whether your hypothesis was
accepted or rejected
Ex: My Hypothesis is accepted because
the plant on the window sill grew 3 cm
but the plant in the closet did not grow.
Do Now:
• Take out your Homework
• Do Now Worksheet on desk
Today’s Aim: Experimental Design
& Interpolating Data
Experimental Design:
• When designing an experiment, a
scientist must test only one factor at a
time.
• Variable: one factor that can exist in
differing amounts that is being tested.
Experimental Design
Control Group
-Constant conditions
- Used for Consistency
and to isolate the
Variable
Experimental Group
- Identical to the
control group
EXCEPT for one
variable being
tested
-Used to generate
results.
Independent Variable
The variable that is changed by the
scientist. For example: amount of
sunlight in our experiment
To ensure a fair test, a good experiment
has only one independent variable. As
the scientist changes the independent
variable, he or she observes what
happens.
Dependent Variable
The scientist focuses his or her
observations on the dependent variable
to see how it responds to the change
made to the independent variable.
For example: the growth of the plant
The new value of the dependent
variable is caused by and depends on
the value of the independent variable
Contols
A condition that is kept constant among
groups in an experiment.
For example: The amount of water given
to each plant
Do Now
Take out “Saving Fred” lab, Pass up
procedure
Focused Free Write in class notes
What is a line graph? Why are they so
important in science? What are some
key elements that all line graphs must
have?
How to make a graph!
It's probably better to do a graph in
pencil first, then in pen.
How to make a graph!
• 1. Collect your data. After you have it
all in one place, you should have one
independent variable (like time) and one
dependent variable (like something you
measure as a function of time).
Making a Graph
• Here are some points we will use as an
example; we've measured position of a
ball as a function of time:
time (s) position (cm)
1
3.0
2
5.5
3
7.5
4
9.0
5
10.0
Making a Graph
2. Determine the range of your data.
In order to determine how big a graph
to make, we need to determine how
much the numbers vary. In this case,
time varies from 1 to 5 seconds, and
position varies from 3.0 to 5.3 cm. We
have to make sure that there is enough
space on the graph to fit all the data
Making a Graph
3. The independent variable (time, in this
case) will go on the x-axis (the one
parallel to the bottom of the page), and
the dependent variable (position, in this
case) will go on the y-axis (parallel to
the left hand side of the page). So,
draw axes that are big enough for all
the data.
Making a Graph
4. Give your graph a Title. Titles of
graphs are usually "Y versus X"; so in
this case, our title is "Position versus
Time." (NOT position divided by time, or
position minus time.)
Making a Graph
5. Label your graph and your axes.
THIS IS VERY IMPORTANT! When
presented with your graph, other people
should be able to figure out what is
plotted without asking you.
Making a Graph
6. Labels on the axes must have units!
So, in this case, the label on the x axis
(the one on the bottom) should be "Time
(seconds)" and the label on the y axis
(the one on the left) should be "Position
(centimeters)."
Making a Graph
7.Remember to write the numbers on
the graph, too. The numbers should be
evenly and logically spaced - what I
mean by this is the following: for our
position data here, the y-axis should be
marked off in increments like
(1,2,3,4,5,6) or (2,4,6,8), NOT (1.3, 2.6,
4.8,...) or anything else weird.
Making a Graph
8. Plot your data. Now, go ahead and
place your data points on the graph.
Make them big enough to be seen, but
not big enough to look like you were
eating pizza while making your graph.
Making a Graph
9. CONNECT THE DOTS! THE ORIGIN IS
NOT ALWAYS INCLUDED AS A POINT! Now
you're done with your graph, but you're not
finished yet.
Making a Graph
10. Think about what your graph means.
What type of relationship do the
variables have?
Use the directions on the previous page to construct
a graph. Here are some points we will use as an
example to draw a graph; we've measured position of
a ball as a function of time:
⦁ time
(s)
⦁ 1
⦁ 2
⦁ 3
⦁ 4
⦁ 5
⦁ position
(cm)
⦁ 3.0
⦁ 5.5
⦁ 7.5
⦁ 9.0
⦁ 10.0
Graphing Terms
• Interpolate: estimating information
within a graph (within the range of data
given)
• Extrapolate: extending the graph to
estimate information (outside the range
of data given)
Questions
1.
2.
3.
4.
5.
Interpolate the position of the ball at 2.5 seconds: ______
Interpolate the position of the ball at 4.5 seconds: ______
Extrapolate the position of the ball at 6.0 seconds: ______
Extrapolate the position of the ball at when it stops moving: ______
Describe in words how the position of the ball is changing with time:
__________________________________________________________________
________________________________________________________
6. What is the variable used to describe the relationship between position and time?
_______________
7. Use the graph to explain how this variable of “speed” changes in this
experiment.__________________________________________________________
_______________________________________________________
8. What is the independent variable? _______________ dependent?_____________
Do Now:
Temperature
(˚C)
-Take out
Homework
-Explain in a full
sentence the
meaning behind
this graph.
Compare and
Contrast data
set 1 and data
set 2
Temperature
Vs Time
Time (min)
19. Graphing
• Direct Relationship: both variables
“move in the same direction” They both
increase or both decrease. As time
increases, the temperature increase.
Inverse Relationship
• Variables “move in opposite directions”.
One variable goes up and the other goes
down. Example: as temperature
increases, density decreases
• One variable changes, but the other
remains the same. As time increase the
size of earth remains the same.
Cyclic: repeats at known
intervals.
Ex: As time goes on the hours of
daylight increase then decrease
at a predictable rate.
Line Graph
Equal Value
Circle Graph (Pie Graph)
• A=50% B=25% C=12.5% D= ______
C
B
D
A
Bar Graph
Do Now:
-Find the folder with your name on it, this is
your seat. Do NOT move or open the folder.
-Put all belongings on a LAB table
-Take out a pencil
-Take out a calculator
-Be silent and have a big smile on your face
when I walk in the room.
-Relax, if you studied you will do AWESOME!
Rate of change
• How fast did
the change happen?
• How much a measurable aspect of the
environment, called a field, is altered
over a given amount of time – years,
hours, or seconds.
The steeper the slope the faster
the rate of change!
If the slope is constant, the rate
of change is also constant
If the slope is exponential or
curved, then the rate of change
is not constant!
A flat horizontal line, means the
that the value is constant over
time and not changing at all
Cyclic Change:
• Changes that repeat over and over in a
known period of time.
• Examples are: seasons, sun motions,
moon and tides
• Most changes are cyclic and they are
very good to use when we are trying
to make predictions
Non-cyclic Changes:
• Changes that do not repeat at all or do
not repeat in a known period of time.
• Some examples of these are:
• Earthquakes and Hurricanes.
Formula:
• Change in field value
Change in time
•
• Formula is on p. 1 in ESRT
Rate of Change questions
• 1. If the greenhouse effect causes the
Earth's average temperature to
increase by a total of 3°F between the
years 1960 and 1990, what is the rate
of temperature change in degrees per
year (°F/year)?
Rate of Change questions
• 2. After a series of earthquakes, a
landsat satellite computes that
California is 15 cm less wide than it was
3 years ago. What is the rate of change
of California's width?
Rate of Change questions
• 3. As hurricane Felix neared the U.S.
coast, air pressure dropped from 996
millibars to 980 millibars in 8 hours.
Calculate the rate of air pressure
change in mb/hour.
Matching Graphs to Situations:
Interpreting Graphs
SBN 2003
Select the graph that best fits
the situation described.
The answer will appear with one
click.
Answer : 1
Riding a bicycle up a steep hill
and down the other side
Answer : 3
The amount of gasoline used
while traveling on level ground
Answer : 1
A candle burning
Answer : 1
A car stops at a stop sign and
then continues the drive
Answer : 3
A wagon is pushed and then
coasts to a stop
Answer : 1
A truck slows down and then
speeds up
Answer : 1
A marble that rolls until it
stops
Answer : 1
A unoccupied tricycle rolls
down a hill into an oak tree
Answer : 2
The level of water in a river
over the year with rains and
dry spells
Answer : 1
A yo-yo moving rhythmically up
and down
Answer : 3
The ocean waves washing away
a sand castle on the beach
Answer : 2
Income earned from an hourly
wage job
Answer : 3
The growth of a tree over
several years
Answer : 3
A dog sleeping in the shade
Answer : 2
The area of a square
Answer : 2
After the plug is pulled, the
water draining from a bathtub
Answer : 3
A speeding car crashes into a
solid brick wall
Answer : 2
Waiting to land, an airplane
circles at a constant speed
Answer : 2
The seat of the ferris wheel at
the county fair
Do Now:
• Take a
Lab from
the Do
Now Desk!
• Begin
reading
the
directions
quietly to
yourself
Do Now:
Take a
Goal/Review
Sheet from
the Do Now
Desk
Station
1
2
3
4
Anthony & Jane
Juilet & Ryan
Joe Kim & Edward
Enis & Kayla
5
6
7
Joe N. & Erick
Byron & Hye Jun
Noah & Emma
8
9
David & Julia
Sienna & Gabby & Diego
Group
Station
1
2
3
James & Vera
Kristen & Roni
Kerry & Nikki
4
5
6
Corinna & Victor
Lisa & Charles
Olivia & Joseph
7
8
Alejandro & Blake
Yessica & Rachelle
9
10
Stephanie & Ari
Paola & Jason
11
Keller & Madeline
Group
Do Now:
Clear your
desk
you need a
pencil and a
Calculator
Sit in Test
Seats
4. CLASSIFICATION:
• To put things into groups.
• We can organize or classify objects according
to some pattern or trend or common
characteristics.
Classification
• The purpose of classifying is to organize
creatures into four different groups.
Remember that creatures can only end
up in one group at the end.
• After you divide them in to two groups,
they can not cross over when you divide
them again.
Rules to Classification
• Start each question with “ Does it have ___.”
• -Do NOT use
size, color or behavior.
• Don’t use the same question twice
• - Good examples are:
Does it have wings? Does it have more than
two legs? Does it have feathers? Does it have
Antenna? Does it have segments? Does it have
scales?
Rules to Classification
• 6) Do NOT use the same question twice
• 7) Do NOT use size, BAD EXAMPLE #1: “Is
it big?”
• 8) Do NOT use color. BAD EXAMPLE #2:
"Is it blue?"
• 9) Do NOT behavior or function, BAD
EXAMPLE #3: "Can it fly?"
• 10) Do NOT use environment, BAD EXAMPLE
#4: "Does it live in the ocean?"
Rules to Classification
Classify these creatures:
Question # 1: ____________________________________________________________
Yes:
No:
Question #2:
____________________________
____________________________
______
Yes:
No:
Don’t cross this
line!
Yes:
Question #3:
_____________________________
_____________________________
____
No:
Do Now:
• Take both sheets on the Do Now Desk
• On the back of the classification
worksheet write the rules for
classification that we learned
yesterday.
Do NOW: Measurements
Worksheet on Do Now Desk
a. What are some measurable
properties?
Think on a daily basis, what might
be some of the things you
measure?
-Mass
-Area
-Temperature-Volume
-Density
-Pressure
b. How do we make measurements?
• Our senses are limited by how sensitive
or by how accurate they are. To get
more detailed information, we use
instruments, such as rulers,
thermometers, x-rays and telescopes
c. Metric System & Unit Conversion
• The fundamental units of the metric
system are:
Grams (g)
For Mass ______________________
• For Length
Meters
(m)
______________________
milliliters (mL)
• For Liquid Volume ________________
Prefix Fun!
• By changing the prefix used with
each unit you can change the size of
the unit. We will use the following
prefixes. (There are others for both
larger and smaller units.)
Kilo(103)
Hecto(102)
Deca- Basic Unit
(101) (100)
Deci- Centi- Milli(10-1) (10-2) (10-3)
Prefix Fun!
• You can remember
this using the
following
sentence:
• King Henry
died, drinking
chocolate milk
Kilo- (103)
Hecto- (102)
Deca- (101)
Basic Unit (100)
Deci- (10-1)
Centi- (10-2)
Milli- (10-3)
• To convert from any unit to any other
unit count how many spaces are
between them and move the decimal
point that far in the same direction.
Let’s look at the meter stick! How many
1
meters (m) are in a meter (m) stick?___
How many centimeters (cm) are in a meter
100
(m)? ___________
• How many millimeters (mm) are in a
10
centimeter (cm) ?__________
Now if
there are 100 cm in a meter and 10 mm
in a cm how many mm are in a m?
1000
__________
• Decimals are used because they are easier to
convert than fractions! In the metric
system we use abbreviations! Let’s fill them
in below!
Length
___ Mass
Liquid Volume
meter__________
m
gram_______
g
liter________
L
mg
millimeter_______
milligram______
milliliter______
mm
mL
cm
centimeter_______
----------------------kg
kL
km
kilometer_______
kilogram______
kiloliter______
Please complete the practice questions 1-15
Do Now
• Open up to classwork section, and
complete the following:
Focused Free Write:
Why do scientist round answers to math
equations? What is the purpose? What
are the rules of rounding?
6. Rounding:
• The first step in rounding is figuring out
what place to round to and where that
place is located. You must remember
these place values:
• 2 , 6 4 3 , 9 7 5 , 8 6 4 . 9 3 1
Rounding Procedure:
• Step 1: Find the location of place that
you are asked to round to. Lets call it:
Sparky.
• Step 2: Look at the number to the right
of this place lets call it the Boss.
• Step 3: If the boss is a 4 or lower,
leave Sparky alone. If the Boss is 5 or
higher, round the Sparky up one value.
Rounding Procedure:
• Here is a rhyme to help you remember:
• “Four and below, let it go. Five and
above give it a shove”
• For Example: Round 7.289 to the
nearest tenth: Answer: 7.3
• Now complete practice problems 1-9!
Do Now
• Have your homework on your desk
• Take out graduated cylinder worksheet
• Focused Free Write: What is mass?
Do Now: In class notes
Section, Round the following
to the nearest TENTH!
• Also, take out HW, add 6pts on point
chart if complete
1) 8.678 = 8.7
2) 99.012 = 99.0
3) 784.555 =784.6
4) 10.99 = 11.0
5 )0.3567 = 0.4
Check your answers
1. 88 mm = 8.8 cm
2. 5.7 km = 5700 m
3. 18,500 ml = 18.5 L
4. 15,300 g = 15.3 kg
5. 0.023 kg = 23,000 mg
6. 0.3 cm = 3.0 mm
7. 5,287,945 mm= 5.287945 km
8. 12,300 ml = 12.3 L
9. 0.007 km = 7,000 mm
10. 0.008 km = 800 cm
Check your answers
11) 6.78: 6.8
12) 8.210:8.2
13) 3.0682: 3.1
14) 82.921: 82.9
15) 15.23: 15.2
16)
17)
18)
19)
75.023: 75.02
46.9: 46.90
32.97045: 32.97
99.9999: 100.00
20) 1.65656565: 1.657
21) 100.967: 100.967 (already there)
22) 0.011223: 0.011
Check your answers
20) 1.65656565: 1.657
21) 100.967: 100.967 (already there)
22) 0.011223: 0.011
23) List two numbers that would round to 8.7:
8.745 & 8.689
24) Explain why 7.93 rounds down to 7.9:
The number to the right of the tenth’s place is
less than 5
25) Explain why 2.85 rounds up to 2.9:
The number to right of the tenth’s place is
greater or equal to 5
What is MASS:
• Is the amount of matter in an object.
• It is how much “stuff” the object is
made of, the number of molecules in it.
How do we measure Mass
• Can we count the atoms? One by one? Lol
Nope! Instead we use a triple beam
balance which gives us a value usually in
grams.
Let’s click here for an interactive triple beam balance!
Is Weight the same as Mass?
Weight is NOT the same as mass, but
weight is used to measure the mass of an
object on the Earth. Think about what
would happen if you weighed your self on
the moon. You would weight less because
there is less gravity pulling you down onto
the scale, even though your mass did not
change.
Let’s check our our weight on the
MOON!!!
8. Temperature:
• It is the amount of heat energy an
object has.
• Typically the faster the molecules
vibrate with in a sample of matter the
hotter it is.
English Units: Fahrenheit Degrees (F°)
• Water Freezes : 32°F.
• Water Boils: 212°F.
Metric Units: Celsius Degrees (°C)
• Water freezes: 0°C.
• Water boils: 100° C.
Kelvin Units (K)
• Absolute zero: 0 Kelvin’s
• Water freezes: 273 Kelvin’s
• Water boils: 373 Kelvin’s
ABSOLUTE ZERO:
• The lowest possible temperature and
occurs when ALL heat is removed.
• It is equal to -272°C.
9. What variable determines the different
phases?
Temperature
What are three states, or phases of
matter?
• Solid (ice) Liquid (water) Gas (water vapor)
11. Area:
• The amount of space a 2-dimensional object
takes up
• For squares and rectangles area is equal to:
LxW
• L: Length, the longer dimension of an 2 D
object usually measured in meters,
centimeters or millimeters.
• W: Width, the shorter dimension of a 2D
object.
• Note that the units will always end up
squared! Example: 4mm x 2mm = 8mm2
11. Area:
Let’s practice using the following steps:
• Step 1: Write the formula
Example: Area = L x W
• Step 2: List all the variables
including the unknown, WITH UNITS.
Example: L = 4mm W= 2mm A= ?
11. Area:
Let’s practice using the following steps:
• Step 3: Plug in the numbers,WITH UNITS.
Example: A=4mm x 2mm
• Step 4: Calculate WITH UNITS.
Example: A= 8mm2
• Practice the two examples on your own!
Do Now: Take one ruler and
one object from the box on
the front table.
Use the ruler to find the volume of
the object you choose. If you can
not use the ruler to find the
volume, explain how you could.
10. Volume:
• The amount of space an
object takes up
• For solid cubes and boxes,
Volume is equal to: L x W x H
Depending on the size of the
object the units may be
either cm3 or m3.
10. Volume:
• But for liquids, volume is measured in
liters using a beaker or graduated
cylinder. There two rules:
1. Always read it at eye level
This is a beaker!
10. Volume:
• 2. You must read the meniscus to obtain
an accurate result. Due to cohesion
(sticky) properties of fluids, the edges
of the fluid touching the glass will
slightly rise.
Meniscus = 73 mL
10. Volume:
It is easier to measure
irregular shaped
objects using fluid
displacement. In order
to measure this
irregularly shaped rock
you would drop it in a
beaker filled with water
and measure the change
in volume.
What factors affect Volume?
• 1)Temperature
•
Heating a material will cause it to expand and
take up more space because the molecules need
more room to move around. Therefore
increasing temperature will increase volume.
T V
• _________________
•
Cooling a material will result in the opposite.
So decreasing temperature will decrease
volume. ____________________
T V
• Think about how your rings fit in the winter…
they seem to be bigger!
What factors affect Volume?
• 2) Pressure:
• Increasing pressure will force molecules
closer together there by decreasing
P V
volume. ______________________
• Decreasing pressure will allow molecules
to spread out and take up more space
thereby increasing volume.
P V
_________________
• Let’s model this with a sponge.
This week’s HW
Monday: Measurement worksheet and
study for quiz
Tuesday: Density Homework Worksheet
Wednesday: No HW
Thursday: Graphing Worksheet
Friday: No HW
Extra Help: Today after school and
tomorrow morning
11. DENSITY
• The amount of matter (mass) in a given
amount of space (volume).
• It tells us how tightly packed the
molecules are, or how close to each
other they are.
• If they are packed tightly, the density
is high.
DENSITY UNITS
• The unit for measuring density is
grams per cubic centimeter, or g/cm³
• Density = Mass
Volume
M
D
V
Step 1
• Write the formula
• Example: Density = Mass/Volume
or
D=M/V
Step 2
• List all the variables including the
unknown, WITH
• Example: D=?
M = 38.0g
V = 12.0cm3
UNITS.
Step 3
• Plug in the numbers, WITH
UNITS.
• Example:
D=38.0g/12.0cm3
Step 4
• Calculate WITH
UNITS.
• Example:
D=3.2g/cm3
Example
If an object has a mass of 13.4
grams and a volume 5.7 cm3 what is
the density?
Solution:
Let’s Practice !!!
• Please complete the worksheet
Do Now:Take out HW
• Quietly look over your notes in prep for
you quiz
• You need a calculator
Do Now: Draw this in your class
work section
Beaker filled with water: Density = 1.0 g/cm3
D= 1.0
g/cm3
D= 3.0
g/cm3
D= 1.5
g/cm3
D= 0.5
g/cm3
D= 0.8
g/cm3
D= 0.2
g/cm3
More on Density
• Each pure substance has its own particular
density and it can be used to help identify
that material at room temperature.
• For example, liquid water has a density of
1g/cm³ because 1cm³ of water weighs 1
gram. One cm³ of water also occupies 1ml.
• solid quartz has a density of 2.7 g/cm³
Mixtures do not have a precise density.
-Fluids tend to layer based on their
density, with less dense fluid on top of
more dense fluid. Can you think of any
examples?
Oil and
Vinegar
!
Let’s check out this video!
•
http://www.eram.k12.ny.us/education/components/docmgr/default.php?sectiondetailid=17500&fileitem=4738&catfilter=445
Factors that affect Density
a. Temperature
• Cooling a material causes its molecules to
move closer together, making its volume
decrease and causing its density to
T VD
increase.
• Heating a material causes its molecules to
move apart making its volume increase and
causing the density to decrease TVD
• Note that Mass is staying the same!!!
So why does density matter?
If a warm gust of wind meets
cold air, will the warm air go
above or below the cold air?
• Since hot air is less dense it will rise!
• And Cold air sinks because it is denser
than warm air
• This happens when
you boil water 
This rising and sinking of fluids
due to density and temperature
differences is called…
A CONVECTION CURRENT!!!
We will touch upon this concept many
times through out the year
Factors that affect Density:
b. Pressure
• Increasing the pressure (squeeze) on a
material causes its molecules to get
pushed closer together, decreasing the
volume, making the density increase.
P VD
• Decreasing the pressure causes the
opposite effect, since molecules move
further apart, it becomes less dense.
• Again, note mass remains the same!
P VD
Do Now: Take out Density of
GUM LAB turn to data.
• Focused Free Write: Take a
look at my awesome Lava
Lamp. Why are the colors
separated? Why do the blobs
move rather than settle? What
processes in earth can we
relate this phenomenon to?
15. Density at Different Phases
• As a material is heated, it changes from
solid to liquid.
• More heat changes the liquid to gas.
The molecules move farther apart, so
the volume increases, causing the
density to decrease.
• Solids are most dense, gases are
least dense
The Only exception to this rule is
water
• As water cools, its volume decreases
until it reaches 4° C.
• As it cools from 4° C to 0° C, its
volume actually increases, so it becomes
less dense again.
• Water is most dense at 4°C, but is still
a liquid.
• This is due to my buddy Mr. Hydrogen
Bond, you will meet him in Chemistry
• Water at 0°C is solid ice, but is less
dense than water, so ice floats!!
• Water is the only material whose solid
form will float in its liquid form.
• This is why the top of a puddle, or a
lake freezes first.
16. Does size affect density of an object?
• You can NEVER change the density of a
material by cutting it into pieces.
• Since change both volume and mass, the
ratio will remain the same, therefore
each small piece will have the same
density as the original large one.
17. Let review some crucial relationships!!!
• Temp.
• Temp.
Density
Density
You must understand and know these by heart!!!
Let review some crucial relationships!!!
• Pressure
Density
• Pressure
Density
You must understand and know these by heart!!!
• As temperature _________________,
Density _____________ this is a
________________ relationship
• As temperature _________________,
Density _____________ this is a
________________ relationship
As pressure
_________________, Density
_____________ this is a
________________ relationship
As pressure
_________________, Density
_____________ this is a
________________ relationship
Do Now: Copy HW
Focused free write: Why does ice
float? Is the Dad’s explanation
correct?
Do Now: Draw how each liquid would layer if
your poured them into the big cylinder
Liquid
A
D= 1.5
g/mL
Liquid
C
D= 5.0
g/mL
Liquid
B
D= 3.0
g/mL
Liquid
D
D= 0.5
g/mL
Density Quiz Tomorrow
10 multiple choice questions
5 short answer question
-Know how to draw how an object will float in water
based on it’s density
-Know how liquids will layer based on density
-Know why ice will float in water
-Know how to calculate density
Know relationships between…
-Density and Temperature
-Density and Mass
-Density and Pressure