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C: 17 Sept. 2010
Homework: Background
info
paragraphs
Objective: SWBAT
test a hypothesis by
collecting, organizing and analyzing
data.
Do
now:
m
D
V
Rearrange this
equation for m= and
V=
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Agenda
I.
Do now
II.
Lab introduction
III.
Perform the lab!
IV.
Data analysis, graphing and
drawing conclusions
V.
Intensive vs. extensive properties
Homework: Week 2/3 Homework p. 1-2
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Density of Pennies Lab
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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 (or mass or volume)
1.
An object with mass of 10.0 g, and
volume of 20.0 mL
2.
An object with mass of10.0 g and
volume of 5 cm3
3.
Calculate the mass of a sample of
matter with a volume of 10.0 cm3 and
density of 2.0 g/cm3
4.
Calculate the volume of a rock with
mass 100.0 g and density 5.00 g/mL.
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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. In your notebook (or piece of paper)
write two hypotheses.
2. Carefully follow the procedure and
collect data in an organized table.
3. Graph your data sets.
4. Write an analysis paragraph describing
your graphed data sets.
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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)
±0.05g
Volume (mL)
±0.5 mL
Density
(g/mL)
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Data to record:
2
Hypotheses
Data
table for pre- and post-1982 pennies
Average
Graphs:
density for each group
mass vs. volume (2 sets of data on
the same axes, do not connect dots!)
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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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So, is
density intensive or extensive?
How do you know? Discuss your
graph, and what a graph of the other
type might look like.
+ Homework: Week 2/3 p. 1-2: Thurs.
Week
2/3 Homework, #6 ADD PICTURES
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C: 17 Sept. 2010
Take
out Homework: Graph of data
Objective: SWBAT
graph data using
Excel.
Do
now: Describe two errors from
your experiment yesterday. How
could you make improvements to
minimize this error?
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Agenda
I.
Do now
II.
Homework check
III.
Graphing in excel
Homework: Write an analysis paragraph
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Making a graph
Follow
along in Excel as Ms. Boiteau
shows you how to enter your data, and
then how to make a graph.
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A: 17 Sept. 2010
Get
out Homework: None!
Objective: SWBAT
graph data and
communicate an analysis in a
complete paragraph.
Do
now: Log into your computer, open
your email, and download your Excel
file from yesterday.
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Agenda
I.
Log in and download
II.
Finish graphing: adding in the “details”
III.
Print
IV.
Analyze graphs and write an analysis
paragraph
V.
Notebooks!
Homework: Finish analysis paragraph, write
a conclusion
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Writing an analysis of your data
Write
a paragraph describing your
two data sets, but not explaining what
the data mean. What data is shown on
your graph? What is the shape of the
data? Slope? Are there any outliers?
What are they?
Writing
a
conclusion
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Restate
hypothesis. Were your hypotheses
supported by your data? Why or why not?
Answer conclusion questions in a paragraph:
 Is
density an intensive or extensive property? How do you
know? Give evidence from your data.
 What elements are pennies made of? One of these elements
has a density of 8.92 g/mL. How do your densities (before
1982 and after 1982) compare with the density of the pure
element? Why do you think this is?
 How do you explain any difference in the density of the two
groups?
 Use the results of this lab to make a hypothesis about how the
composition (make-up) of the two groups of pennies is
different. What do you think changed in 1982 (aside from
density)? Why? (Connect conclusion to background info!!)
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Homework
Finish
your analysis paragraph
Write
a conclusion
Due Monday.
Transfer
notes into your new
notebook (optional)
(or bring $10 Monday for your
notebook)
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Write a Lab Report
Title
(incl. name, date, partner’s
names)
Background
Objective
Due
(You
info (from notes, etc.)
(no hypothesis)
Friday
can start the procedure if you
want!)
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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.
Link
these concepts and terms
together into a coherent paragraph
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Objective and Hypothesis
Explain
what the purpose of the
experiment or what goals you have in
completing the lab. What do you
hope to accomplish?
Predict
the results of the experiment.
Explain your reasoning behind your
hypothesis.
State
your independent, dependent
and controlled variables.
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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.
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
25
30
35
Mass (g)
Figure 1: Mass in grams vs. volume in mL of two groups of pennies (pre-1982 and
post-1982) with a best-fit line.
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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 (ouliers).
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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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Lab
Report Due Next Monday
This is your ONLY draft
Typed!!
This will be used as a ‘pre-test’ for
your ability to write a lab report
 Will
be compared to your lab reports as the
year goes on to measure your progress!
 This does count as a lab grade!
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Hand
back background info
paragraphs!