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Synthesis and Characterization of Gold Nanoparticles
Terms:
Breakdown
method
Build-up method
Control variable
Dependent
variable
Drug delivery
Independent
variable
Nanomedicine
Nanoparticle
Nanorods
Nanotechnology
Nanometer (nm)
Reducing agent
Replication
UV-visible
spectroscopy
Wavelength
Figure 1. Size scale for nanoparticles as compared to other
materials (top). Nanoparticles can be adapted to include
biomolecules, drugs, or targeting and imaging molecules to form
nanotechnology-based drug delivery platforms (bottom).
https://ocg.cancer.gov/e-newsletter-issue/issue-11/translating-cancer-targetsnanotechnology-based-therapeutics#Figure%201%20nano
Introduction Nanoscience and nanotechnology are the science, engineering and technology of
working with extremely small things in the range of 1 to 100 nanometers (nm) (6). One nanometer is a
very small unit because it takes 109 nanometers to make one meter and 25,400,000 nm to make one
inch. Richard Feynman is often credited as being the father of nanotechnology because of a speech he
gave in 1959 entitled “There’s Plenty of Room at the Bottom”. Feynman speculated about the ability to
visualize and manipulate individual atoms and molecules which seemed pretty crazy at the time.
Although it took another twenty plus years, the development of the scanning tunneling microscope and
atomic force microscope made it possible to not
only see individual atoms but also to move them
around. Figure 2 shows you the first creation
using nanotechnology.
What’s so special about nanotechnology?
It’s not just that the particles are extremely small
such as individual atoms but more that extremely
small particles less than 100 nm in diameter, have
Figure 2. The first created nanostructure
which spelled IBM in 35 xenon atoms on a
unique properties compared to their larger
copper substrate. http://www.nano.gov/nanotechcounterparts. For example, metallic nanoparticles
101/what/working-nanoscale
may have a lower melting point, a higher surface
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area per unit of volume or mass, special optical properties, unique mechanical strengths and/or
magnetic properties that their bulk metal counterparts lack. These unique physical and chemical
properties of the nanoparticles are often highly desirable for industrial and medical applications.
If I asked you what color gold atoms
were, you would probably say “gold or
yellow” because you’re thinking of gold
jewelry or a gold watch, right? While a
large sample of gold always appears gold
or yellow, a solution of gold nanoparticles
(GNPs) may appear blue, red, or purple
depending on the size of the
nanoparticles in the solution (1). Why do
gold nanoparticles appear these different
colors? When gold nanoparticles are
similar in size to a wavelength of visible
light (400–750 nm), they interact with the
light in interesting ways. The volume and
shape of the nanoparticles in a solution
determine the color of the solution. Look
at Figure 3. As the diameter of a gold
nanoparticle increases, the
wavelength of maximum
absorbance gradually shifts to
longer wavelengths in the visible
spectrum.
Figure 3. The size of the gold nanoparticles in
solution determines the wavelength of maximum
absorbance and their color. From Ref. 4 LizMarzán , L.M. ( 2006 ) Langmuir , 22: 32 – 41 .
These unique properties of
nanoparticles are one of the
fundamental attractions in working
with them and have been for
centuries – even before anyone had
heard the word nanoparticle.
Nanotechnology is evident in many
old churches. Although medieval
artisans were unaware that they
were using nanotechnology, the
ruby red color used in stained glass
Figure 4. Stained glass rosace in the Cathedrale Notrewindows during the Middle Ages
Dame de Chartres (France), color changes depend on
was an early application of
the size and shape of gold and silver nanoparticle.
nanotechnology (Figure 4). Modern
chemical studies have shown that these vivid colors resulted from the different sizes and shapes of the
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gold and silver nanoparticles in the windows. Today, nanomaterials can not only be efficiently
synthesized but also modified with various chemical functional groups and/or conjugated with
antibodies, ligands or drugs of interest. These modified gold nanoparticles have yielded new potential
applications in biotechnology, magnetic separation, targeted drug delivery, improved diagnostic imaging
and use as vehicles for gene and drug delivery to cells.
Synthesis of Gold Nanoparticles Today you
will be synthesizing gold nanoparticles. Each
nanoparticle contains hundreds to thousands of
atoms. Unlike small molecules that have a specific
chemical formula, nanoparticles vary in the number
and arrangement of their atoms - even in a
supposedly pure batch. In order to make
nanoparticles, two general methods are commonly
used. The first is the breakdown (top-down)
method in which an external force is applied to a
solid that breaks it into smaller particles. The second
is the build-up (bottom-up) method that produces
nanoparticles starting with atoms of gas or liquid
which then undergo atomic transformations or
molecular condensations (Figure 5).
The synthesis of nanoparticles using the
microwave for heating has become a popular option
in recent years and it has the typical microwave
Figure 5. Schematic representation of the
advantages; it’s simple and quick. In the microwave
‘bottom up’ and top-down’ methods of
approach, temperatures may go above their boiling
nanoparticle synthesis.
points as the liquid becomes superheated due to the
increased absorption of the thermal energy by the solvent.
Nanomedicine In recent years, gold nanoparticles have begun to be actively used in
nanomedicine for diagnostic and therapeutic purposes. Specialized antibodies that bind to protein
markers for breast cancer or for other cancer types can be attached to nanorods, gold nanoparticles
shaped like a rod. If the antibodies bind to protein markers in a blood sample, scientists can then
examine the light properties of the conjugated nanorods. Since each protein-nanorod combination
scatters light in a unique way, a more precise diagnosis can be made.
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Nanoparticles between 10 and
150 nm in diameter are just the right size
to pass through gaps in the blood vessels
supplying tumors but do not significantly
penetrate healthy blood vessels or tissue.
By loading the particles with
chemotherapy drugs— established cancer
killers—one can (at least in principle)
deliver the drugs very specifically to tumor
cells without damaging healthy cells.
Figure 5 illustrates the process. In the
future, nanomedicine may include
advanced drug delivery systems, new
therapies, and in vivo imaging but
understanding the issues related to
toxicity and the environmental impact of
nanoscale materials may prove to be
major hurdles.
Figure 5. The blood vessels in solid tumors have
irregular linings, with gaps much bigger than the ones
in healthy blood vessels. Nanoparticles (NP) less than
250 nm in diameter can pass through those gaps and
accumulate in the tumors through a purely physical
phenomenon called the enhanced permeability and
retention effect.
Two resources to help you
understand how gold nanoparticles are
made and their significance in medicine:
https://www.youtube.com/watch?v=QorK2X7GsVU
o ‘The Future of Nanogold’ - 4 min video discussing GNP properties & uses
https://doi.org/10.1063/PT.3.1678
o Grossman, J. H. and S. E. McNeil. 2012. ‘Nanotechnology in Cancer Medicine’
Physics Today 65: 38 – 42.
o This article is posted on Blackboard under Labs to Read and Week of March 6th
Data and Calculations In order to find the size of gold nanoparticles in your solution, the light
properties of the solution are analyzed by spectroscopy. You only need to measure three values of your
GNP solution:
1. The wavelength of maximum absorbance (spr)
2. The absorbance at the wavelength of maximum absorbance (Aspr)
3. The absorbance at 450 nm
Finding the GNP’s Diameter in nm The size and concentration of GNPs can be determined
directly from UV-Vis spectra. As the diameter of a gold nanoparticle (GNP) increases, the wavelength of
maximum absorbance gradually shifts from 505-510 nm to longer wavelengths in the visible spectrum.
The longer the wavelength of maximum absorbance, the greater the diameter of the GNPs. Although
the wavelength of maximum absorbance can be used to determine the size of the gold nanoparticles
(GNPs), this doesn’t mean that every single GNP in your solution has exactly the same diameter. The
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calculated diameter from spectroscopy represents the predominant GNP size in the solution based on its
light properties. There are two Tables in the Appendix for finding the GNP diameter based on the
wavelength of maximum absorbance.
For particles with an spr> 525.0 nm, use Table 1 in the Appendix to determine the diameter
of your GNPs. For example, if the wavelength of max absorbance is 540.4, then the size of
the calculated size of the nanoparticles would be 68 nm. What would be the GNP diameter
if spr was 563.8 nm? Did you say 96 nm?
For smaller gold nanoparticles, use Table 2 in the Appendix which is based on the ratio of
Aspr/A450. As GNPs get smaller, the diameter value should be considered just an estimate.
For smaller GNPs, the surface effects get progressively more and more significant yet they
were ignored in the methods used to derive Tables 1 and 2.
Determining the Concentration (M) Remember Beer’s law (Equation 1)? Assuming that the
path length is 1 cm so that it drops out of the equation, you can rearrange Beer’s Law into Equation 2.
EQUATION 1:
Abs = * b * c
EQUATION 2:
Concentration (M) = A450/450
Where: Abs at the anal. wavelength
=Extinction coeff. for molecule (GNP)
b = Path length (1 cm for all of our cuvets)
c = Concentration of molecule in soln.
Where: A450 = Abs of soln at 450 nm
450 = Ext. coeff. for GNPs at 450 nm
Once you’ve calculated the diameter of your GNPs, use Table 3 in the Appendix to find the extinction
coefficient for your GNPS at 450 nm. Then you can use Equation 2 and the absorbance at 450 nm to
calculate the concentration of your nanoparticles. For example, if your GNPs had a diameter of 42 nm
and an absorbance of 0.250 at 450 nm, then the 450 would be 5.74E+09, and the GNP concentration
would be 4.36E-11.
References:
1. McFarland A.D., et al., Color my Nanoworld, J. Chem. Educ., 2004, 81 (4), p 544A
2. Horikoshi S., Serpone N., Introduction to Nanoparticles, in Microwaves in Nanoparticle
Synthesis, First Edition. Published 2013 by Wiley-VCH Verlag GmbH & Co. KGaA
3. Bogunia-Kubik K, Sugisaka M. From molecular biology to nanotechnology and nanomedicine.
BioSystems. 2002;65: 123–138.
4. Moghimi SM. Nanomedicine: current status and future prospects. The FASEB Journal. 2005;19:
311–330. doi:10.1096/fj.04-2747rev
5. Liz-Marzán , L.M. Tailoring surface plasmons through the morphology and assembly of metal
nanoparticles. Langmuir, 2006 Jan 3;22(1):32-41
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6. http://www.nano.gov/ Accessed on Sept 18, 2016.
7. Haiss, W., N. T. K. Thank, J. Aveyard and D. G. Fernig. 2007. Determination of Size and
Concentration of Gold Nanoparticles from UV-Vsi Spectra. Anal. Chem. 79: 4215-4221.
8. Doss, H. M. 2016. Using Gold Nanoparticles to Kill Cancer.
http://www.physicscentral.com/explore/action/pnb-nanotherapy.cfm . Accessed Sept 16, 2016.
Check your P1000 Technique before Working on your Synthesis Rxns: The number one reason
students are unable to detect gold nanoparticles after their synthesis experiment is pipetting errors.
The ratio between the gold solution and the reducing agent needs to be very precise or the gold
nanoparticles will either precipitate out of solution, or no synthesis will occur. So your first task today is
to double check that your P1000 technique is accurate.
1.
Go to one of the lab balances with your lab instructor. Your lab instructor will tell you a volume
in microliters (uL). Set the P1000 to the correct volume and show your lab instructor how you
set the volume. Is the volume set correctly? Well done!
2. Tare a weigh boat on the balance. With your lab instructor watching, pipette your given volume
of distilled water into the weigh boat. Since water has a density of 1 gram/milliliter, one
milliliter (or 1000 microliters) or water should have a mass very close to 1.000 grams. The mass
of your sample should be within 3-4 milligrams (+.003) of your target mass. If not, ask your lab
instructor where you might have gone wrong and try again. The most common errors are:
Not setting the volume dial correctly
Not depressing the plunger to the correct stop point
Releasing the plunger too quickly so that you end up with some air in the pipette tip
3. Dump the water from the weigh boat in the sink and dry out the weigh boat with a paper towel.
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Procedure:
Today’s lab uses a liquid phase (bottom-up) approach to investigate how changes in the GNP
synthesis reaction affect the size and optical properties of the synthesized gold nanoparticles. Each
group will study one independent variable for its effect on the size and concentration of GNPs. You
could test 1) the time of reaction; 2) temperature of the reaction; or 3) pH of the reaction. All three
independent variables should be done by your lab section.
Designing Your Experiment Designing an experiment is often the most important part of any
experiment because a well-designed experiment makes it easier to interpret the data in the end.
Complete Table 1 on the Data Sheet as you plan your experiment. You may do up to ten determinations
(10 test tubes) for your experiment. You may want to have your lab instructor look over your plan to
make sure that it is a good one. Here are some considerations to think about when designing your
experiment:
Every group should run a positive control. The positive control reaction is known to reliably
produce gold nanoparticles. Positive controls assure you that the reaction is working as
anticipated. The positive control tube (as shown on the top line in Data Table 1) includes: 1 mL
of 1 mM HAuCl4, 1 mL of 4 mM sodium citrate (Na3C6H5O7) and 3 mLs of distilled water and is
boiled for 10 minutes.
Control Variables: To reduce the gold ions to gold atoms, a reducing agent that is oxidized is
required to drive the reaction. Sodium citrate is the standard reducing agent and the one that
you will use today. In previous semesters, we tested other reducing agents (fructose, glucose,
etc.) but none of them reliably produced gold nanoparticles. Any potential variable that is held
constant across all of the tests or determinations is called a control variable.
The best experiments have only one independent variable and all the other variables are held
constant across all of the determinations.
o Time of Synthesis: Suggested times might range between 3 and 15 minutes.
o Temp of Synthesis: The standard protocol requires the solution to be boiled for ten
minutes. What would happen if the temperature is lower than 100oC? Test three
temperatures lower than 100oC and see what happens to the gold nanoparticles. You
may be surprised.
o pH: Two solutions of 4 mM HNO3 and 4 mM NaOH are available for you to use. Because
total volume is an important control variable, keep the total volume of the reaction the
same across all determinations. To change the pH, just use the acid or base in place of
some of the water. For example, to test the effect of acidic conditions on GNP
synthesis, you could replace 0.5, 1.0, 1.5, etc. mLs of the water with 4 mM nitric acid
(HNO3).
Each determination should be identical to all of the other determinations EXCEPT for the
independent variable. For example, if you are studying pH, the time of synthesis, amount of the
gold reactant, the total volume, etc. should all be identical between all of the determinations.
These are control variables. Only the independent variable (pH) should differ between
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determinations. This makes the data much easier to interpret because only the pH was
different between your determinations.
Repeating a test is essential in science. This is called replication. For example, if you are
examining the effect of the time of synthesis as your independent variable, each time you test
should have at least two determinations.
Studying the Synthesis of Gold Nanoparticles
1. Plan your experiment by completing Table 1 on the Data Sheet. Have your plan checked by your lab
instructor before you get started. Time to get that lab coat, goggles and gloves on for the day.
2. Add ~300 mL water to a 600 mL beaker and cover it with a watch glass. Heat the water to boiling on
a hotplate – no stirring necessary. While the water is heating, prepare your test tubes according to
your experimental design in Table 1 on the Data Sheet. Use a P1000 to add the different reagents.
Remember how to use a P1000? If not, ask your lab instructor for a refresher. The ratio between
the gold reactant and reducing agent is critical when making GNPs. What messes up the ratio the
most? Poor pipetting skills.
3. Get the spectrophotometer ready to analyze your nanoparticle solutions. Turn on the laptop, sign in
and open the Logger Pro software. Connect the SpectroVis Plus Spectrophotometer to the USB port
of the laptop. From the File Menu, select ‘New’.
If you receive a message that the Logger Pro software is not working when you
first open it, here is what to do. Unplug the spec at the USB port and plug it into
a different USB port. Then, close the software and reopen it. This usually takes
care of the problem but if it doesn’t, check that all of the connections are secure.
4. Retrieve two empty cuvettes, being careful NOT to touch the clear sides of the cuvettes where the
light passes through. Hold the cuvette up to the light and look for fingerprints, scratches, dust or
drops of dried liquid – anything that might interfere with the passage of light. Clean the cuvette if
necessary.
5. Fill a cuvette ~3/4 full with the blank solution and place it in the Spec so that one of the clear sides is
facing the white arrow.
A reference or blank solution in spectrophotometry includes everything EXCEPT the molecule
that you will be measuring. Today the reference solution should be a mixture of 4 mM
sodium citrate and distilled water – the solution containing your nanoparticles.
6. From the Experiment menu, choose ‘Calibrate’ then ‘Spectrometer 1’. Once the warm-up period is
complete, select ‘Finish Calibration’, and OK. You only need to calibrate these specs one time when
you first turn them on.
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7. Once the water is boiling, remove the watch glass from the beaker and place your
prepared test tubes in the boiling water bath according to your experimental
design. Start timing. Be sure to have a test tube holder ready to remove the
tubes from the boiling water. Observe the color of the reaction during the
Figure 5. Test tube holder.
nanoparticle synthesis.
8. When the reaction time is complete, remove your test tubes from the water to a test tube rack to
cool. Observe them for a color change that should occur within 15 minutes. Unless the reaction
time is your independent variable, be sure to remove all of your test tubes at the same time.
9. Remove a sample from the positive control and record: 1) its color; 2) the wavelength of maximum
absorbance (analytical wavelength); 3) the absorbance value at the analytical wavelength; and 4)
the absorbance at 450 nm. Analyze all of the remaining test tubes as you did for the positive control
using the same cuvette. Record your results.
10. If possible, compare your data with other groups who selected the same independent variable, if
possible. Did your results agree? Discuss possible sources of error If they didn’t agree.
11. Write a lab report analyzing your data on the synthesis of nanoparticles and submit it through
SafeAssign on Blackboard under Post-Lab Assignments. Consult the lab report evaluation form
posted in the ‘Lab Reports’ folder on Blackboard.
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Gold Nanoparticles Data Table
Name _________________________________
4 mM
Test 1 mM
Na
Tube HAuCl4 Citrate
#
(mL)
(mL)
H2O
(mL)
4 mM
HNO3
Acid
(mL)
3.0
0
4 mM
Total
NaOH
volume
Base
(mL)
(mL)
1
1.0
1.0
0
5.0
2
1.0
1.0
5.0
3
1.0
1.0
5.0
4
1.0
1.0
5.0
5
1.0
1.0
5.0
6
1.0
1.0
5.0
7
1.0
1.0
5.0
8
1.0
1.0
5.0
9
1.0
1.0
5.0
10
1.0
1.0
5.0
Time
of
Rxn
(min)
Temp.
of Rxn
(oC)
Wavelength
of
Absorbance Absorbance
Maximum
at peak nm at 450 nm
Abs. (spr)
(nm)
GNP
diameter
(nm)
GNP Conc.
(M)
10.0
10
Appendix
spr (nm)
Diameter
(nm)
spr (nm)
Diameter
(nm)
spr (nm)
Diameter
(nm)
525.0
525.6
526.2
526.8
527.5
528.2
32
34
36
38
40
42
534.9
535.9
536.9
538.0
539.2
540.4
58
60
62
64
66
68
552.1
553.8
555.7
557.6
559.6
561.7
84
86
88
90
92
94
528.9
529.6
530.4
531.2
532.1
533.0
533.9
44
46
48
50
52
54
56
541.6
542.9
544.3
545.7
547.2
548.8
550.4
70
72
71
76
78
80
82
563.9
566.2
568.6
571.1
573.7
576.5
579.3
96
98
100
102
104
106
108
Table 1. Tabular values for determining the size of gold nanoparticles in water using the spectrophotometer.
for particles larger than 35 nm. The spr is the wavelength of maximum absorbance in nanometers. (7)
Aspr/A450
1.10
1.19
1.27
1.33
1.38
1.42
1.46
1.50
1.56
1.61
1.65
1.69
Diameter (nm)
3
4
5
6
7
8
9
10
12
14
16
18
Aspr/A450
1.73
1.80
1.86
1.92
1.96
2.00
2.03
2.07
2.10
2.12
2.15
2.17
Diameter (nm)
20
25
30
35
40
45
50
55
60
65
70
75
Table 2. Ratio of the absorbance of
GNPs at the Aspr to the absorbance at
450 nm (A450). (7)
11
diameter e450
(nm)
(1/M-cm)
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
4.25E+05
1.49E+06
3.62E+06
7.20E+06
1.26E+07
2.03E+07
3.07E+07
4.43E+07
6.15E+07
8.27E+07
1.09E+08
1.39E+08
1.76E+08
2.18E+08
2.67E+08
3.24E+08
3.87E+08
4.60E+08
5.41E+08
6.31E+08
7.31E+08
8.42E+08
9.64E+08
1.10E+09
1.24E+09
1.40E+09
1.58E+09
1.76E+09
1.96E+09
2.18E+09
2.41E+09
2.66E+09
2.93E+09
diameter e450
(nm)
(1/M-cm)
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
3.21E+09
3.52E+09
3.84E+09
4.18E+09
4.54E+09
4.92E+09
5.32E+09
5.74E+09
6.18E+09
6.65E+09
7.13E+09
7.65E+09
8.18E+09
8.74E+09
9.32E+09
9.92E+09
1.06E+10
1.12E+10
1.19E+10
1.26E+10
1.33E+10
1.41E+10
1.48E+10
1.57E+10
1.65E+10
1.73E+10
1.82E+10
1.91E+10
2.00E+10
2.10E+10
2.19E+10
2.29E+10
2.40E+10
diameter e450
(nm)
(1/M-cm)
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
2.50E+10
2.61E+10
2.71E+10
2.82E+10
2.93E+10
3.05E+10
3.16E+10
3.28E+10
3.40E+10
3.52E+10
3.64E+10
3.77E+10
3.89E+10
4.02E+10
4.14E+10
4.27E+10
4.40E+10
4.53E+10
4.65E+10
4.78E+10
4.91E+10
5.04E+10
5.17E+10
5.30E+10
5.43E+10
5.56E+10
5.69E+10
5.82E+10
5.94E+10
6.07E+10
6.19E+10
6.31E+10
6.44E+10
Table 3. Molar extinction coefficients of spherical gold nanoparticles in water. In conjunction with the absorbance at 450 nm and a standard
path length of 1.0 cm, the concentration (M) of the GNPs can be calculated using Equation 4 in the text. The data have been experimentally
verified in the d range from 5 – 100 nm. For particle diameters smaller than 5 nm, the values should only be considered as an estimate since
surface effects may get increasingly important in this size region.
12
1. Title Page – 2pts
- Informative title for lab report - Name, course and lab section, date,
lab instructor’s name and name of lab partner
2. Abstract – 4pts
200 words
- Brief description of experiment, results and main conclusions in under
3. Introduction – 10pts
- Purpose for the experiment described in the report - Brief
background description on nanotechnology (applications) and nanoparticles (physical and
chemical properties, size & unique optical properties - Review of chemical concepts &
techniques relevant to the experiment (importance of positive control & one independent
variable, synthesis of gold nanoparticles, using a spec, using wavelength to determine GNP size
- Hypothesis for the experiment
4. Experimental Method – 8pts
- Lab procedures are outlined in paragraph form - no bullets!
- Experiment is well-designed - No results or data are reported in this section - Cite lab manual
5. Results – 8pts
- All raw data from experiment is presented in a table or graph, as
appropriate - Tables/figures are clear and easy to interpret with labeled axes and columns and
units clearly specified - Graphs/tables are numbered with a meaningful title and legend
explaining what should be seen by the reader (trends in data) - All calculations from the data
are included with 1 sample calculation shown with full explanation of all variables - No methods
or discussion of the data are presented in the Results section - Summary of the Results in text
format concludes the section
6. Discussion – 11pts
- Begin with the purpose of the experiment and a statement of the
hypothesis - Did your experiment support your hypothesis? Explain why your data did (or did
not) support your hypothesis use specific data in support of each conclusion - Correct
interpretation of experimental results (what do your results indicate?) - Discussion of possible
errors that may have affected results; ways to prevent errors in the future
- Potential improvements or suggestions for additional experimentation?
7. Format – 4 pts
- Individual sections are labeled - Sentence format with passive voice (no
first person!) and correct verb tense are used - Carefully proofread for grammatical & spelling
errors
8. References Cited – 2 pts
- All information from other sources is cited using ACS format
(Please no Wikipedia! - Cite lab manual and at least 2 additional sources
9. Self-Evaluation – 1 pt
- Use a copy of this rubric to self-evaluate your lab report. In other
words, if you were grading your lab report, how many points would it earn?
Self-Evaluation (50 pts possible): _______
TOTAL POINTS (50 pts possible): _______
In the entire article, Bender explains how the Americans considered themselves as
superior to other nations. They traveled to other countries as explorers and adventurers
and found the people going on with their political, social and economic life. The people
in all nations had their culture or their beliefs and values. Thinking that they were
superior to the natives, as well as considering that the indigenous people’s way of life
was primitive, they convinced them to adapt to the American way of life. For example,
they asked them to stop worshiping their gods and adjust to Christianity when they first
arrived Korea at 1866.
In India they were able to convince the Cherokees by offering them education for
instance how to read and write and talking to them about democracy made the Cherokees
think that the United States people were superior. The Americans occupied the natives
land by first colonizing the natives’ minds and making the people think that they were
more superior to them. I think people in most countries that the Americans occupied did
not at first know their intention. It was much later that they realized that the Americans
had grabbed their land and they had become American’s slaves or laborers.
I think land occupation was the most critical factor in the United States drive for
expansion according to Bender’s article. The U.S. explorers realized that other countries
especially the African nations were rich for agriculture, mineral and other resources they
were unaware of and unexploited. They knew the only way to exploit the resources
found in other countries without having to pay them back was to occupy the land. The
Americans considered themselves more intelligent than the indigenous people. They
colonized their minds by making them abandon their culture and adopt the American. For
example, in most countries, men engaged in hunting and fighting the enemies while
women worked on the farms. The American’s convinced the men to abandon their
hunting activities and work on the farms while women did domestic chores. It was now
easy to occupy their land.