LESSON PLAN
| SCIENCE
KS3
SCIENCE
A B O U T T H E AU T H O R : Dr Joanna L. Rhodes M.Chem, D.Phil, MRSC is a teacher of science at Shelley College, Huddersfield.
Digging deep
Get students delving into the fascinating world of archaeology to help
them understand essential aspects of biology, chemistry and physics
Why
teach
this?
It is perhaps
surprising that
scientific discoveries
can be made about
archaeological sites,
artifacts and ancient
cultures by using
science and satellite
imagery that is
accessible to students
in KS3; this kinesthetic
learning experience
will really stimulate
the senses.
Whether it is Tomb Raider, Indiana Jones or the historical discovery of
Tutankhamen’s tomb, archaeology and the idea of ancient civilisations is
inherently exciting. I have found simply writing this lesson quite a thrilling
experience, which led me to spend longer than I should attempting some
amateur archeology on Google Earth and simply walking round Angkor Wat in
Cambodia, somewhere it has always been an ambition of mine to visit. As well
as an appreciation of archaeology this lesson is designed to put KS3 biology
(food tests) chemistry (fermentation and production of ethanol) and physics
(atomic structure and isotopes) into a fascinating real world context to improve
kinesthetic learning opportunities and raise engagement.
Students will construct a layer cake that represents a dig site and learn about
how to plan and map a dig. They will carry out chemical food tests with an
archaeological theme and prepare their own sample of ethanol in a simulation
of an experiment carried out to resurrect ancient Andean yeast cells. An
independent learning investigation of carbon-14 dating leads to a deeper
understanding of atomic structure and the half-life of radioactive isotopes and
finally Google Earth could create a real archaeologist – could anyone in your
class discover something completely new?
S TA R T E R
AC T I V I T Y
Layer cake archaeology
This well described activity
from the Archaeological
Institute of America simulates
a dig site [AR1]. Students
learn basic archaeological
terms, skills, and concepts
through excavating and eating
a stratified cake. They use
teamwork to uncover the
layers, and they can observe
that information is lost when
layers are mixed. The way
you prepare the cake can
differentiate this activity for
students of a wide range of
abilities and can facilitate a
number of different learning
objectives. Choose the
objective(s) before you
prepare the cake; these
could include one or more
of the following:
• Introduction to the principle
of stratigraphy (or a build up
of layers of soil and debris on
top of the artifacts).
• Illustrate the importance
of context in interpreting
various artifacts.
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• Model excavation strategies
of digging horizontally,
excavating one layer at a
time, and leaving part of
a square unexcavated until
the stratigraphy has been
revealed in another part.
• Show how digging
carelessly can mix layers and
disguise chronological and
cultural change.
• Allow students to
experience in a kinesthetic
way the fact that excavating
an archaeological site
destroys it, so that afterward
there is no possibility of
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LESSON PLAN
| SCIENCE
checking information
not recorded.
• Show the importance of
carefully recording the finds
in each layer.
The dig could contain a range
of different types of artifacts
including sections of wall,
pots, knives and human
remains(burial site or graves).
This is simulated very well
using Lego pieces but be sure
to introduce them between
the layers of the cake after it
has been cooked!
MAIN
AC T I V I T I E S
1. Chemical
archaeology
Chemistry is now used
extensively on archaeological
digs to study many aspects
of ancient life. One of the
most fascinating is the study
of pottery vessels and food
containers as chemical
residues from food have been
found to survive in the porous
pottery surface for several
thousand years. The school of
Chemistry at Bristol University
provides an interesting
introduction to this branch of
chemistry [AR2].
In this activity students
investigate the diet of ‘ancient’
people using chemical food
tests. To prepare for the
activity break some pottery
medium sized fragments
(about 5-10cm2). The best
HOME LEARNING
Carbon dating is a tool used to date objects that contain organic material that was once
alive. It measures the ratio between carbon-12 and carbon-14 a radioactive isotope that
is only renewed in animals and plant while they are alive and exchanging carbon with
the environment. Once the animal or plant has died, the amount of carbon-14 gradually
decreases by radioactive decay, a process with a known half-life. The amount that is
left, tells us the approximate age of the artifact. Ask students to draw a diagram of the
subatomic particles in the three isotopes, 12C, 13C and 14C, and to explain the similarities
and differences between their atoms. Secondly ask students to estimate the age of a
range of artifacts such as carved wooden objects or mummified remains of humans or
animals based on the percentage of 14C left in them using the graph provided on BBC
Bitesize [AR8]. As an extension question, ask them if they can use the graph to work out
the half-life of carbon-14.
type of pottery to use is
various plant pots. We found
a local garden centre was be
willing to donate some of their
breakages which also gave us
a realistic range of colours and
glazes for our dig. Soak the
plant pots in four food-based
solutions or paint on the
solutions and then leave
to dry overnight in air or a
warm oven.
Food type 1 – glucose solution
Food type 2 – protein solution
(egg whites)
Food type 3 – starch solution
Food type 4 – vitamin C
(orange juice or ascorbic
acid solution)
In the lesson students become
chemical archaeologists
and test the ‘food’ residues
on each of the pots. Each
piece of pottery should be
photographed, numbered
and bagged before and after
the tests to ensure results are
recorded against the correct
fragment. Once the pieces
have been numbered and
bagged, each piece of pottery
should be individually washed
into a separate beaker using
a small amount (25cm3) of
solution of water. All the
washings should be retained
and labeled with the number
of the corresponding piece of
pottery. The solution should
then be carefully tested in
2cm3 portions, which should
allow for the experiment to be
repeated twice for each piece
of pottery.
The chemical tests are as
follows [AR3]:
• Benedict’s test for reducing
sugars (glucose). Add 2cm3 of
the sample solution to a test
tube. Add an equal volume of
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Benedict’s solution to the test
tube and swirl the mixture.
Leave the test tube in a
boiling water bath for about 5
minutes observing any colour
change. If sugar is present it
will change from blue to green
and possibly even to yellow
or red.
• Biuret test for protein. Add
2cm3 of the sample to a test
tube and add 2cm3 of Biuret
Reagent. Shake well and
allow the mixture to stand for
5 minutes. Look for colour
changes in the solution. If
proteins are present it will
range from no colour change
(blue) to pink to deep violet.
• Iodine test for starch. Add
2cm3 of the sample to a test
tube and add 5-10 drops of
iodine solution. If starch is
present the solution will turn
blue/black.
• DCPIP (2,6
dichlorophenolindophenol)
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EXTENSION FOR GIF TED
A N D TA L E N T E D P U P I L S
With the availability of satellite images and Streetview
images from Google Earth along with accurate
measuring tools, it is no longer necessary to visit an
archaeological site in order to draw a map or plan or
even to take a look around. Provide a piece of graph
paper and ask students to create a plan of an ancient
site such as Pompeii, the Nazca lines, Macchu Picchu,
Stonehenge, and one of the most impressive I have
seen is Angkor Wat in Cambodia. Not only is the
level of detail available on Google Earth incredible
but you can also visit inaccessible minor temples
in the jungles many of which also have streetview
and 360° images. New archeological features have
been discovered using Google Earth. Students who
think they may have discovered their own might
be interested in the ArchAtlas Project [AR9] which
is collating images and essays on some of the
discoveries made by Google Earth users.
test for vitamin C [4]. Add
2cm3 of DCPIP solution to
a test tube. Add the food
solution one drop at a time,
to a test tube containing a
light blue solution of DCPIP.
If the extract is acid the colour
will change from blue to red.
Continue to add more and
see if the colour disappears
altogether. Decolourisation
of DCPIP shows that a vitamin
C is present.
You could consider whether
to give students the artifacts
in a shoebox simulated dig
[AR5] as described by the
Archaeological Institute of
America, to add a greater
degree of realism. Also
be clear on the method of
feedback. Students could
present their work as a report,
or deliver a PowerPoint to a
sponsor or give a talk in the
style of a museum lecture.
2. Explore ancient
alcoholic drinks
Share with students an article
from Scientific American [AR6],
which describes how yeasts
from fermentation vessels in
an Andean tomb were scraped
from the pottery and repaired
using microbiology. The
resurrected microbes were
characteristic of those found in
saliva and even faeces, proving
how these ancient people used
these bodily wastes to start the
fermentation of their alcoholic
beverage known as chicha. In
this activity provide students
with sample of ‘ancient’ yeast
(use ordinary brewers yeast),
which they can use to ferment a
sugar solution. This can be done
using a method described by
the Nuffield Foundation [AR7].
It would be advisable to set the
fermentation process going at
the end of a lesson as it will take
a few days for sufficient alcohol
to form. Next lesson, students
can smell the fermented
solution, which will now smell
distinctly alcoholic. The Nuffield
method also describes how to
isolate and purify the ethanol
using distillation. This is an
excellent opportunity to set
up laboratory glassware that
students may not have seen
or used before and to inspire
an interest in chemistry and in
particular, organic synthesis.
Once isolated the alcohol
could be tested using acidified
potassium dichromate. In this
test 2cm3 of the alcohol is
ADDITIONAL RESOURCES
[1] Layer cake archaeology ow.ly/M4uD308ImUU
[2] Archeological chemistry ow.ly/9C5t308ImXx
[3] Chemical food tests ow.ly/WSzH308ImZD
[4] DCPIP test for vitamin C ow.ly/23lq308In1E
[5] Shoebox dig ow.ly/wwKn308In4I
[6] Andean yeast resurrection ow.ly/97WW308In7R
[7] Fermentation of sugar solution using yeast ow.ly/wtFl308Inat
[8] Carbon dating ow.ly/vMNp308IndG
[9] ArchAtlas ow.ly/ZtKU308Ing0
teachwire.net/secondary
placed in a boiling tube in a
water bath at about 60°C. 1cm3
of potassium dichromate made
up using 1 mol dm-3 sulfuric acid
is added. The colour change
from bright orange to green/
blue confirms the presence
of ethanol.