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Do Now: 6 minutes
1.
Get out your “Analyzing a Graph…”
worksheet from yesterday.
2.
Find the poster your didn’t analyze.
3.
Finish the worksheet, and hand it in
on the front table.
4.
Sit down, and take out your
notebook. Copy the objective.
Smile, it’s Friday!
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Density of Pennies Lab
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Intensive vs. extensive properties
Intensive
property: a physical
property that does NOT depend on
how much of a substance you have.
Ex: temperature, velocity, melting
point
Extensive
property: a property that
DOES depend on how much you have.
Ex: mass, length, volume
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Intensive or extensive?
I
weigh 130 pounds.
The
car is moving 50 miles per hour.
The
length of a marathon is 24.6
miles.
The
Ice
I
density of water is 1.0 g/mL
melts at 0oC.
drank one liter of soda. (burp!)
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Density
A
physical property of matter
mass(g)
density 
3
volume(mL /cm )
The
mass per volume of a substance.
Units: g/mL
1
or g/cm3
mL = 1 cm3
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Calculate Density
Mass
10.0
= 10.0 g, volume = 20.0 mL
g, 5 cm3
Calculate
the mass of a sample of
matter with a volume of 10.0 cm3 and
density of 2.0 g/cm3
Calculate
the volume of a rock with
mass 100.0 g and density 5.00 g/mL.
+ Homework
Week
6 Homework, #5-6
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The phenomenon
In
1982, the density of pennies
changed.
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Your challenge:
Determine, empirically, the
density of
pennies before and after 1982.
1. Write a materials list and procedure.
Include ALL your steps. Be thorough!
2. Carry out your procedure.
3. Record and organize data into a chart
and graphs. Describe your data in a
paragraph.
4. Analyze your data in a paragraph.
5. Make a conclusion summarizing your
data and answering questions.
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Some details
How
can you determine the volume of
a penny?
Displacement
Calculate
the density of 2, 3, …10 pre1982 pennies, and 2, 3, …10 post-1982
pennies. Make a neat table and
graph.
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An example of a good table.
Table 1: Mass, volume and density of pre-1982 pennies
Number of
pennies
2
3
4
5
6
7
8
9
10
Mass (g)
Volume (mL)
Density
(g/mL)
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Things to write in your notebook:
 An
excellent materials list and procedure
 Complete
data tables (title, headings, units,
calculations, NEATLY!)
 Complete
graphs: mass vs. volume and
EITHER mass vs. density or volume vs.
density, with title, axis labels and units
A
written description of your data.
A
written analysis of your data
A
conclusion based on guiding questions.
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Your homework
To
write a lab report.
First
Draft (neatly hand-written or
typed) due:
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So, is
density intensive or extensive?
How do you know? Discuss your
graph, and what a graph of the other
type might look like.
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By the end of class…
Materials
list and procedure (incl. how to
make calculations!)
Data
table for pre- and post-1982 pennies
2
graphs: mass vs. volume AND either
Mass vs. density OR volume vs. density
With a sentence describing each graph.
You
can start an analysis and conclusion like
we practiced yesterday.
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Homework
Week
6 Homework: #5-6
2
graphs: mass vs. volume AND either
Mass vs. density OR volume vs.
density
With a sentence describing each
graph.
You
can start an analysis and
conclusion like we practiced
yesterday.
Mass vs. Volume of Pre- and Post-1982 Pennies
Pre-1982 Pennies
Post-1982 Pennies
4
Volume (mL)
3.5
3
2.5
2
1.5
1
0.5
0
0
5
10
15
20
Mass (g)
25
30
35
Mass vs. Density of Pre- and Post-1982 Pennies
Pre-1982 Pennies
10.0
Post-1982 Pennies
9.0
Density (g/mL)
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
0
5
10
15
20
Mass (g)
25
30
35
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With your group:
Fix
your graphs. Draw a best-fit line.
Write
a one-paragraph analysis for
each graph. Describe BOTH lines
for each graph.
Trend
Shape of line
Outliers: points that are way off the
line.
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Title
Your
lab report should be titled with a
title of your choosing.
It
should be relevant to the lab and
should not just be the same as the title
of a handout your teacher gave you.
Do
not have it on a separate title
page.
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Background Information
Explain
any important concepts that
are central to understanding the
experiment.
In
paragraph form, define any
scientific terms necessary for
understanding the lab.
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Objective (NO hypothesis)
Explain
what the purpose of the
experiment or what goals you have in
completing the lab. What do you
hope to accomplish?
(No
hypothesis)
IV: number
DV: density
of pennies
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Write a Lab Report
Title
(incl. name, data, partner’s
names)
Objective
(no hypothesis)
Background
DUE
info (from notes, etc.)
TOMORROW
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Procedure
 For
a lab where you have designed the
procedure, include a detailed and
complete account of every single step
you completed during the lab, including
how to make calculations. Be sure to
include proper names for pieces of
equipment!
 If
you have followed a procedure given
by your teacher, write a summary of
what you did. Do not rewrite the given
procedure word for word.
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Data and Results
 Include
any charts, graphs, tables,
technical drawings, observations, or
diagrams in this section. Include a one
sentence caption for each.
 Data
should be presented neatly, and
with the use of computer software when
possible.
 If
any calculations were necessary
during this lab, include them here.
 DO
NOT explain the data.
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Analysis
Describe
any patterns or trends in the
data. Point out any relevant
characteristics and comparisons that
you see. Do not attempt to explain
them, simply note them.
Note
the existence of any data that
does not seem to fit the overall
patterns/trends.
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Conclusions
 Draw
conclusions from the patterns and
observations you noted in the analysis section.
Explain why the patterns you saw occurred.
 Was
the experiment successful at completing
the objectives above? Explain why or why not.
 Reflect
on your hypothesis. Was it correct?
Why or why not?
 Was
there any significant error in your
experiment? Propose some possible sources of
error and explain how they might be improved.
 Answer
questions (4) in lab handout in
paragraph form.
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On a separate sheet of paper…
Write
the first draft of your lab report.
Work
on your own.
You may listen to music as long as I
can’t hear it.
Label
each section.
Be
careful to include EVERY part
listed in your lab report guide.
First
draft due: next Thursday, Oct. 22