Observations
Check the three observations that are GOOD
observations applicable to this lab. Underline
QUANTATIVE observations.
□ The pennies are a circle
□ There is stuff (corrosion) on the pennies and that will
get my hands dirty
□ The graduated cylinders are plastic
□ The average penny weights between 2.5-3.2 grams
□ The coins do not have ridges
□ The corrosion on the pennies may change the
density because it isn’t a pure sample
□ A stack of pennies will need at least 30 ml of water in
the graduated cylinder to cover the pennies when I
find their volume.
Observations
Check the three observations that are GOOD
observations applicable to this lab. Underline
QUANTATIVE observations.
□ The pennies are a circle
□ There is stuff (corrosion) on the pennies and that will
get my hands dirty
□ The graduated cylinders are plastic
■ The average penny weights between 2.5-3.2 grams
□ The coins do not have ridges
■ The corrosion on the pennies may change the
density because it isn’t a pure sample
■ A stack of pennies will need at least 30 ml of water in
the graduated cylinder to cover the pennies when I
find their volume.
Hypothesis
• Put a check next to the BEST hypothesis for this
Question
□ If I calculate the density of the pennies, then I
think the pennies will be made of copper
because their color matches copper.
□ If I measure the mass of the pennies without
corrosion, then the density will be different then
dirty ones because the dirt adds extra mass.
□ If I measure the mass and the volume, then I can
calculate the density because the formula is D =
m/v.
Hypothesis
• Put a check next to the BEST hypothesis for this
Question
■ If I calculate the density of the pennies, then I
think the pennies will be made of copper
because their color matches copper.
□ If I measure the mass of the pennies without
corrosion, then the density will be different then
dirty ones because the dirt adds extra mass.
□ If I measure the mass and the volume, then I can
calculate the density because the formula is D =
m/v.
Experiment
1) Use the digital balance to
measure the mass of the
pennies.
2) Make sure the balance is
measuring in grams.
3) Zero or Tare out the weighing
cup (used to protect the scale).
4) Place 10, 15, & 20 pennies in
the cup and record mass in the
data table.
5) Put 50.0 ml of water in the
graduated cylinder.
6) Be sure to get down to eye
level, place it on a flat surface
and read the bottom of the
meniscus when pouring our
water.
7) Hold the tube at an angle and
slide the pennies (10, 15 and
then 20) into the graduated
cylinder to make sure it doesn’t
splash.
8) Again, using the technique in step
6 read the final volume of the
cylinder.
9) Subtract the final volume from the
initial (starting) volume and record
in the data table in ml.
10) Repeat 3 times for each set of
pennies and find the averages by
adding the numbers and dividing
by the total trials for both mass
and volume
11) To calculate density, divide
average mass by the average
difference in volume.
12) Record the Density in g/ml in the
data table.
13) Compare the density you find with
the reference table to determine
the kind of metal and record it in
the data table.
Experiment
1) Use the digital balance to
measure the mass of the
pennies.
2) Make sure the balance is
measuring in grams.
3) Zero or Tare out the weighing
cup (used to protect the scale).
4) Place 10, 15, & 20 pennies in
the cup and record mass in the
data table.
5) Put 50.0 ml of water in the
graduated cylinder.
6) Be sure to get down to eye
level, place it on a flat surface
and read the bottom of the
meniscus when pouring our
water.
7) Hold the tube at an angle and
slide the pennies (10, 15 and
then 20) into the graduated
cylinder to make sure it doesn’t
splash.
8) Again, using the technique in step
6 read the final volume of the
cylinder.
9) Subtract the final volume from the
initial (starting) volume and record
in the data table in ml.
10) Repeat 3 times for each set of
pennies and find the averages by
adding the numbers and dividing
by the total trials for both mass
and volume
11) To calculate density, divide
average mass by the average
difference in volume.
12) Record the Density in g/ml in the
data table.
13) Compare the density you find with
the reference table to determine
the kind of metal and record it in
the data table.
Experiment
1) Use the digital balance to
measure the mass of the
pennies.
2) Make sure the balance is
measuring in grams.
3) Zero or Tare out the weighing
cup (used to protect the scale).
4) Place 10, 15, & 20 pennies in
the cup and record mass in the
data table.
5) Put 50.0 ml of water in the
graduated cylinder.
6) Be sure to get down to eye
level, place it on a flat surface
and read the bottom of the
meniscus when pouring our
water.
7) Hold the tube at an angle and
slide the pennies (10, 15 and
then 20) into the graduated
cylinder to make sure it doesn’t
splash.
8) Again, using the technique in step
6 read the final volume of the
cylinder.
9) Subtract the final volume from the
initial (starting) volume and record
in the data table in ml.
10) Repeat 3 times for each set of
pennies and find the averages by
adding the numbers and dividing
by the total trials for both mass
and volume
11) To calculate density, divide
average mass by the average
difference in volume.
12) Record the Density in g/ml in the
data table.
13) Compare the density you find with
the reference table to determine
the kind of metal and record it in
the data table.
Experiment
1) Use the digital balance to
measure the mass of the
pennies.
2) Make sure the balance is
measuring in grams.
3) Zero or Tare out the weighing
cup (used to protect the scale).
4) Place 10, 15, & 20 pennies in
the cup and record mass in the
data table.
5) Put 50.0 ml of water in the
graduated cylinder.
6) Be sure to get down to eye
level, place it on a flat surface
and read the bottom of the
meniscus when pouring our
water.
7) Hold the tube at an angle and
slide the pennies (10, 15 and
then 20) into the graduated
cylinder to make sure it doesn’t
splash.
8) Again, using the technique in step
6 read the final volume of the
cylinder.
9) Subtract the final volume from the
initial (starting) volume and record
in the data table in ml.
10) Repeat 3 times for each set of
pennies and find the averages by
adding the numbers and dividing
by the total trials for both mass
and volume
11) To calculate density, divide
average mass by the average
difference in volume.
12) Record the Density in g/ml in the
data table.
13) Compare the density you find with
the reference table to determine
the kind of metal and record it in
the data table.
Conclusion
I reject my hypothesis. My data did not
support that pennies were made of copper.
My density was between 7.1 & 7.2 which
matched Zinc the closest. The pattern that I
noticed is that it didn’t matter how many
pennies I used, I still got the same answer. In
conclusion, pennies from 1993-94 are made
of zinc.
Conclusion
I reject my hypothesis. My data did not
support that pennies were made of copper.
My density was between 7.1 & 7.2 which
matched Zinc the closest. The pattern that I
noticed is that it didn’t matter how many
pennies I used, I still got the same answer. In
conclusion, pennies from 1993-94 are made
of zinc.
Errors
An error that I made in my measurement is that I
didn’t weigh my pennies when they were dry and
that extra mass could have messed up my
density. Another error could have been that
there were water droplets on the side of the tube
and when I slide the pennies in, it pushed extra
water into the volume. Last, I didn’t always
remember to get down to eye level and look at
the meniscus. This would have explained why
my volume wasn’t consistent. A suggestion for
next time is it to test pennies that are older to
see they are also made of zinc.
Errors
An error that I made in my measurement is that I
didn’t weigh my pennies when they were dry and
that extra mass could have messed up my
density. Another error could have been that
there were water droplets on the side of the tube
and when I slide the pennies in, it pushed extra
water into the volume. Last, I didn’t always
remember to get down to eye level and look at
the meniscus. This would have explained why
my volume wasn’t consistent. A suggestion for
next time is it to test pennies that are older to
see they are also made of zinc.
For Further Investigation
• If you are denser than the liquid you will
sink. The only 2 that are more dense are
gold and platinum.
• OR!!!
If there is no for further investigations
question by the teacher, tell where you
would see it in real life