TABLE OF CONTENTS
Task
Title
C1
Osmosis in Living Tissue
C2
Catalytic Activity of Enzyme
C4
Passing Electricity through Everyday Substances
C5
Do All Conductors Obey Ohm’s Law?
C6
Composting Bioreactor
C7
Ultraviolet (UV) Radiation Protection of Sunglasses
C8
Extracting DNA from Fruits
E3
How Cross-linking Changes the Properties of a Polymer
Integrated Science
Sample SBA Task
Module C1: Water for Living
Osmosis in living tissues
Teacher Notes
Osmosis is the movement of water through a selectively permeable membrane, from a
solution of higher water potential to a solution of lower water potential. It provides the
primary means by which water is transported into and out of cells.
In this experiment, students will put samples of potato tissues in sucrose solutions of various
concentrations and observe their behaviour. They have to find in which sucrose concentration
the sample of potato tissue shows neither an increase nor a decrease in length and hence to
deduce the water potential of the potato tissue.
Curriculum Link
C1: Water for Living
1.2 Movement of water in and out of cells by osmosis
Pre-laboratory Preparation
1.
2.
Ask students to find out from textbooks or other reference sources the meaning of
osmosis and its importance in biological systems.
Ask students to devise plans to investigate how the potato tissue behaves in sucrose
solutions of various concentrations and hence to find the water potential of the potato
tissue in terms of the concentration of sucrose solution.
Pre-laboratory Talk
1.
2.
3.
4.
Conduct a brief revision on osmosis.
Demonstrate how to prepare a potato cylinder using the cork borer.
Draw students’ attention to the safe handling of cork borer and razor blade.
Ask students to suggest ways to present the results and to determine the water potential
of the potato tissue.
Time Required
Pre-laboratory talk: 10 minutes
Experiment and report writing: 65 minutes
Grouping
Students may work individually or in groups of two to three.
Teacher Notes – C1
1
Integrated Science
Sample SBA Task
Technician Notes
1.0 M sucrose solution can be prepared by dissolving 342 g of sucrose in water and making
up to 1 L.
Laboratory Report
If students are asked to write a detailed report, the report should include the following items:
1.
Title
2. Aims
3.
Theory/Background (optional)
4.
Apparatus and materials
5.
Design of the experiment
6.
Procedure
7.
Precautions
8. Results (including data and observations)
9.
Discussion (including sources of error and improvements to be made)
10. Conclusion
11. Questions for further thought (optional)
Remarks
Depending on the ability of the students, there may be variations for this investigation, such
as:
1.
for high-achieving students, inform them of the purpose of this investigation and
provide them with a list of apparatus; ask them to devise the set-up and procedure for
the investigation (Version 1 of Student Handout);
2.
for students of average ability, a detailed worksheet can be provided to guide them step
by step (Version 2 of Student Handout).
Suggested Solutions to Questions for Further Thought
1.
Besides measuring the length of the potato cylinders, what other parameter can you
measure in order to determine the water potential of the potato tissue?
Measuring the weight of the potato cylinders can be used to determine the water
potential of the potato tissue. When the potato cells lose water in a solution of lower
water potential, the whole potato cylinder becomes lighter. Likewise, the potato cylinder
gets heavier when it is placed in a solution with higher water potential because water
will move into the cells.
Teacher Notes – C1
2
Integrated Science
Sample SBA Task
Suggested Mark Allocation
Area A (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Competence in handling pipette

leveling of the liquid to the graduation mark of
the pipette

proper draining out of the ‘last drop’ from the
pipette
Measuring the length of potato cylinders

blot-drying the potato cylinder before
measuring its length

taking measurements with a precision within
that of the ruler
Carrying out the experiment safely

handling cork borer safely

handling razor blade safely
Performing the experiment in an organised and
efficient way

proper labeling of boiling tubes and pipettes

keeping a record of the data in an appropriate
way
Keeping work area neat and tidy
TOTAL:
Teacher Notes – C1
3
2
Integrated Science
Sample SBA Task
Area B (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Experimental design

independent and dependent variables

assumptions made in the investigation
Experimental plan

using sucrose solutions of various
concentrations

immersing potato cylinders of the same length
in the sucrose solution for a suitable length of
time
Presentation of results


making appropriate use of table and graph to
present data
recording readings accurately (in appropriate
units)
Interpretation of results

accounting for the changes in length of potato
cylinders in terms of osmosis

determining the water potential of potato tissue,
and expressing it in terms of the concentration
of sucrose solution
Evaluation of experimental procedure

discussion of the sources of experimental error

suggestions for improvement
TOTAL:
Teacher Notes – C1
4
2
Integrated Science
Sample SBA Task
Module C2: Balance within Our Body
Catalytic activity of enzyme
Teacher Notes
Starch acts on iodine to give the characteristic blue-black colour of the standard iodine test. In
the presence of an enzyme, amylase, starch is hydrolysed to give predominantly maltose,
some glucose as well as other simple sugars. These products do not react with iodine to give
the blue-black colour.
In this experiment, students are required to study the effect of temperature on amylase activity.
A small amount of amylase is used to act on a given quantity of starch at different
temperatures. When the starch is almost completely hydrolysed, the reaction mixture will
give a negative result to the iodine test (absence of blue-black colour). The reciprocal of the
time for the first instant of the absence of the blue-black colour gives an indication of the rate
of the enzymatic reaction. From the experimental findings, students should be able to deduce
the optimum temperature for amylase activity on starch. They should also recognise the
importance of optimum temperature for metabolic reactions within the body.
Curriculum Link
C2: Balance within Our Body
2.2
The role of enzymes in metabolism; the effect of temperature on enzyme
activity
Pre-laboratory Preparation
1.
2.
Ask students to devise plans to study the effect of temperature on enzyme activity.
Ask students to carry out an information search on chemical structure and specificity of
enzymes.
Pre-laboratory Talk
1.
2.
3.
4.
5.
6.
Conduct a brief revision on enzyme properties and factors affecting enzymatic
reactions.
Discuss with students how to monitor the rate of a chemical reaction.
Ask students to suggest the operating temperatures for the investigation.
Remind students that keeping the amylase and starch solutions in a water bath for
sufficient time are to ensure the solutions attain the desired temperature.
Remind students of safety issues related to the use of hot plate and hot water bath.
Remind students NOT to spill iodine solution onto clothes.
Teacher Notes – C2
1
Integrated Science
Sample SBA Task
Time Required
Pre-laboratory talk: 10 minutes
Experiment and report writing: 60 minutes
Grouping
Put students in groups of three. Each student in a group will be required to work on two given
temperatures. All data collected from the three students will be pooled together and used in
writing the laboratory report.
Technician Notes
A stock iodine solution is prepared by dissolving 1 g iodine and 2 g potassium iodide in 1 L
of distilled water.
In carrying out the iodine test for starch, it is advisable to use a very dilute iodine solution.
Prepare the dilute iodine solution by adding 0.5 ml of the stock iodine solution to 10 ml of
distilled water.
A spot colour made up by mixing 0.01% of starch solution and iodine solution may be used
as an arbitrary standard for the absence of starch.
Amylase solution should be freshly prepared.
Laboratory Report
If students are asked to write a detailed report, the report should include the following items:
1.
Title
2. Aims
3.
Theory/Background (optional)
4.
Apparatus and materials
5.
Design of the experiment
6.
Procedure
7.
Precautions
8. Results (including data and observations)
9.
Discussion (including sources of error and improvements to be made)
10. Conclusion
11. Questions for further thought (optional)
Teacher Notes – C2
2
Integrated Science
Sample SBA Task
Remarks
Depending on the ability of the students, there may be variations for this investigation, such
as:
1.
for high-achieving students, inform them of the purpose of this investigation and
provide them with a list of apparatus; ask them to devise the set-up and procedure for
the investigation;
2.
for students of average ability, a detailed worksheet can be provided to guide them step
by step.
If time allows, students should be encouraged to repeat the experiment at other temperatures
so as to find out the optimum temperature for amylase activity.
Suggested Solutions to Questions for Further Thought
1.
Why does the dark-blue colour of the iodine mixture not appear as mentioned in Step 3?
When the starch is completely hydrolysed, no starch is left to react with iodine solution
to give the dark-blue colour.
2.
What is the implication of the experimental findings on biochemical (metabolic)
reactions within the body?
Most of the metabolic reactions taking place in the body are catalysed by enzymes.
The activity of enzymes plays a very important role in regulating metabolism, thus
maintaining balance within the body. An enzyme works best at an optimum temperature
and the rate of the enzymatic reaction is the highest under this condition. Most of the
enzymes found in the body work best at about 37 oC which is the normal body
temperature.
3.
Account for the temperature dependency of the catalytic activity of enzymes in terms of
chemical bonding and structure.
Enzymes are protein in nature. When the temperature rises, the substrate and the
enzyme molecules have greater kinetic energy. This increases the chance of colliding
with each other to form an enzyme-substrate complex and hence the rate of reaction
increases. The reaction rate reaches the highest at the optimum temperature. However,
further increase in temperature beyond the optimum temperature breaks the hydrogen
bonds and other intramolecular attractions which maintain the specific 3-D structure of
the enzyme molecule. In this way, the enzyme is denatured and becomes mal-functional.
Thus, the enzyme activity drops dramatically when the temperature exceeds the
optimum temperature (Fig.1).
Teacher Notes – C2
3
Integrated Science
Sample SBA Task
Rate of reaction
Heat energy
causes more
collisions
between
enzyme and
substrate
0
10
Optimum temperature
Enzymes denature
at high
temperatures so
rate falls rapidly
20
40
30
50
60
o
Temperature / C
Fig. 1
Effect of temperature on enzyme activity
References
1.
2.
http://www.rsc.org/education/teachers/learnnet/cfb/enzymes.htm
http://en.wikipedia.org/wiki/Enzyme
Teacher Notes – C2
4
Integrated Science
Sample SBA Task
Suggested Mark Allocation
Area A (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Competence in handling pipette

leveling of the liquid to the graduation mark of
the pipette

proper draining out of the ‘last drop’ from the
pipette
Measuring the time for the disappearance of starch
in the reaction mixture

carrying out the test for starch quickly at
2-minute intervals

appropriate use of the stopwatch
Carrying out the experiment safely

Handling hot water bath safely

No spilling of iodine solution onto clothes
Performing the experiment in an organised and
efficient way

proper labeling of test tubes and pipettes

keeping a record of the data in an appropriate
way
Keeping work area neat and tidy
TOTAL:
Teacher Notes – C2
5
2
Integrated Science
Sample SBA Task
Area B (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Experimental design

independent and dependent variables

control set-up and precautions
Presentation of results

making appropriate use of table and graph to
present data

recording readings accurately (in appropriate
units)
Interpretation of results

the temperature and amylase activity
relationship
Making inferences and conclusions

reaching overall conclusion on the effect of
temperature on enzyme activity

relating the optimum temperature of enzyme
activity to metabolic reactions within the body
Evaluation of experimental procedure

discussion of the sources of error

suggestions for improvement
TOTAL:
Teacher Notes – C2
6
2
Integrated Science
Sample SBA Task
Module C4: Chemical Patterns
Passing electricity through everyday substances
Teacher Notes
In this experiment, students will pass electricity through everyday substances, and classify
them as good or poor electrical conductors. They will then conduct an experiment on the
electrolysis of an aqueous sodium chloride solution, and will be asked to provide an
explanation for the reactions that occur during the electrolysis. Students will acquire the skills
of handling multimeters and setting up circuits for electrolysis, and the ability to make
deductions on reactions occurring during electrolysis.
Curriculum Link
C4: Chemical Patterns
4.5
Electrolysis and the ionic theory
C5: Electrical Enlightenment
5.2 Application of electrolysis: decomposition of substances
E3: Chemistry for World Needs
3.2
Production of chlorine by electrolysis of brine
Pre-laboratory Preparation
1.
2.
Ask students to find from reference books possible ways for measuring electrical
conductivity of substances. (Remind students NOT to conduct the experiments at home
using the a.c. mains.)
Ask students to carry out an information search on electrolytes.
Pre-laboratory Talk
1.
2.
3.
4.
5.
6.
7.
8.
9.
Carry out a demonstration of how to use a multimeter and a power supply unit. Discuss
how to select the appropriate scale on the multimeter. Remind students of safety issues
relating to the use of electricity.
Ask students to state the relationship between resistance and conductance of a
substance.
Ask students to propose ways of measuring the resistance of liquids and solutions.
Explain to students the meaning of 5% aqueous solution.
For more able students, ask them to measure the resistance of other substances
commonly encountered in daily life.
Remind students about the particles of matters they have come across, including atoms
(eg metal atoms) and molecules (eg water molecules and glucose molecules). Through
this experiment, student will be introduced to some charged particles in matters – ions,
and they will experience the process through which scientists discovered ions.
Draw students’ attention to the proper way of smelling gases.
Tell students that chemical changes can be described concisely using chemical/word
equations.
Suggest possible ways of recording experimental results and presenting experimental
findings, e.g. taking photographs of the observations, presenting findings using posters.
Teacher Notes – C4
1
Integrated Science
Sample SBA Task
Time Required
Pre-laboratory talk: 15 minutes
Experiment: 25 minutes for Part I
25 minutes for Part II
Discussion/debriefing: 10 minutes
Grouping
Put two to four students in a group (depending on the availability of multimeters, power
supply units and electrolysis cells).
Technician Notes
In Part I, students may need help in preparing the powder samples (using a pestle and mortar
set) and in preparing the aqueous solutions (weighing solid substances and dissolving them in
water).
A 9V battery pack can be used if the number of power supply units is insufficient.
In Part II, chlorine gas will be liberated in the electrolysis. Ensure that the laboratory is well
ventilated or the experiment is conducted in a fume cupboard.
Laboratory Report
If students are asked to write a detailed report, the report should include the following items:
1.
Title
2. Aims
3.
Theory/Background (optional)
4.
Apparatus and materials
5.
Design of the experiment
6.
Procedure
7.
Precautions
8. Results (including data and observations)
9.
Discussion (including sources of error and improvements to be made)
10. Conclusion
11. Questions for further thought (optional)
Students can also be asked to present their findings using posters and/or PowerPoint slides.
Teacher Notes – C4
2
Integrated Science
Sample SBA Task
Remarks
For Part I, students may notice that the measured resistance of a substance depends on factors
such as the distance between the two carbon rods, the concentration of the solution used, the
contact areas between the carbon rods and liquid/solution used. Students can suggest possible
ways of controlling the variables in the experiment.
For Part II, students may notice that electrolysis will not take place unless a certain voltage is
applied. This is due to over-voltage for the liberation of gaseous products in electrolysis.
Students are not required to have this knowledge. The chlorine liberated in the experiment is
irritating and causes choking. Students should avoid smelling it directly.
Suggested Answers to the Questions
Part I:
1.
What is the relationship between the resistance and conductance of a substance?
The higher the resistance the lower the conductance of a substance and vice versa. So a
good electrical conductor has a low resistance.
2.
Which substances in Table 1 are electrical conductors?
Stainless steel ruler, sodium chloride solution (5%) and water (very poor electrical
conductor).
3.
Which of these substances is/are electrolyte(s)? Explain briefly.
Sodium chloride. It cannot conduct electricity in solid state but conducts electricity in
aqueous solution.
4.
Find in your textbook or in any other reference material, the explanations for
(i) the electrical conducting properties of substances, and
(ii) the different behaviour of electrolytes and non-electrolytes with electric current.
(i) Some substances have mobile charged particles (electrons or ions). These charged
particles make it easy for electricity to flow through the substances.
(ii) The electrolytes contain mobile ions when in molten state or aqueous state while
the non-electrolytes do not contain mobile ions for the conduction of electricity.
Teacher Notes – C4
3
Integrated Science
Sample SBA Task
Part II:
1.
Based on the experimental results, deduce the gases liberated at the positive and
negative electrodes.
Positive electrode: chlorine (It is greenish yellow in colour, bleaches the pH paper and
has a choking smell.)
Negative electrode: hydrogen (It is colourless and burns with a ‘pop’ sound.)
2.
Write chemical (word) equations for the reactions occurring at the positive and negative
electrodes.
Positive electrode: 2Cl(aq) → Cl2(g) + 2e
chloride ions → chlorine gas + electrons
Negative electrode: 2H+(aq) + 2e → H2(g)
hydrogen ions + electrons → hydrogen gas
3.
What are the ions present in sodium chloride solution? Why is sodium metal not formed
at the negative electrode in the electrolysis?
Na+, Cl H+ and OH ions
Sodium is a very reactive metal. Sodium ions cannot be easily discharged if the
electrolysis is conducted in aqueous solutions.
Suggestions for Further Investigation
Teachers may ask students to further explore the action of electricity on substances by
working on the following variations of the experiment:
1.
Compare the electrical resistance of:

aqueous solutions of sodium chloride of different concentrations

aqueous solutions of salts of the same concentration

aqueous solutions of salts with singly-charged and multiple-charged ions
2.
Investigate how the results of the electrolysis would be affected by varying:

the concentration of the sodium chloride solution

the voltage applied to the electrolysis cell

the pH of the sodium chloride solution
Teacher Notes – C4
4
Integrated Science
Sample SBA Task
Suggested Mark Allocation
Area A (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Handling and using a multimeter

selecting the appropriate range of the scale

connecting wires correctly
Measuring the resistance

cleaning the surface of the substances where
appropriate

cleaning the carbon rods
Preparing the aqueous solutions for resistance
measurements and for electrolysis

weighing solid correctly

using appropriate apparatus to make solutions
Conducting the electrolysis experiment

setting up the apparatus properly

having correct circuit wiring and applying an
appropriate voltage
Conducting the tests on the gases collected

taking correct steps in testing the gases
TOTAL:
Teacher Notes – C4
5
2
Integrated Science
Sample SBA Task
Area B (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Devising an appropriate experimental procedure for
measuring electrical properties (resistance) of liquids
and solutions
Presentation of results for Part I

recording the multimeter readings correctly

presenting the data appropriately
Interpretation of results for Part I

making logical and correct inferences about the
electrical conducting properties of electrolytes
Presentation of results for Part II


recording the observations on electrolysis
properly
recording the observations for the tests of gases
properly
Interpretation of results for Part II

giving the correct/logical inferences about the
gaseous products from results of the tests

deducing the ions that may be present in the
sodium chloride solution
TOTAL:
Teacher Notes – C4
6
2
Integrated Science
Sample SBA Task
Module C5: Electrical Enlightenment
Do all conductors obey Ohm’s law?
Teacher Notes
This experiment consists of two parts. The first part is a simple standard set-up to repeat
Ohm’s experiment to investigate the relationship between the voltage across a conductor and
the current flowing through it. The second part is a modified version to show that some
conductors do not follow Ohm’s law if certain conditions (e.g. temperature) are not kept
constant. Students should be able to verify Ohm’s law in the first part, and discover
discrepancies in the second part and provide an explanation for the discrepancies. In this
experiment students will practise the skills needed to connect circuits according to circuit
diagrams given and take readings at suitable intervals. Students should also develop the skills
to plot graphs to a suitable scale and to interpret the results. They should be aware that not all
mathematical relationships in science are linear.
Curriculum Link
C5: Electrical Enlightenment
5.4 Ohm’s contribution to current electricity
Pre-laboratory Talk
1.
2.
3.
4.
5.
6.
Remind students of the common errors in connecting a circuit - wrong connection of the
positive and negative terminals, and incorrect series or parallel connection of voltmeters
and ammeters.
Remind students to check their circuits before connecting to the power supply.
Remind students to use the d.c. supply of the power pack in Part B because a d.c.
ammeter and voltmeter are used.
Remind students NOT to touch the nichrome wire and the light bulb during the
experiment as they might get very hot.
Remind students to take readings at suitable intervals. If the current is adjusted at 0.1 A
interval, there is not much change of voltage; if the adjustment of current is at a large
interval, some important features of the relationship might be missed.
Remind students to plot graphs to a suitable scale.
Time Required
Pre-laboratory talk: 10 minutes
Experiment and report writing: 65 minutes
Grouping
Put two to four students in a group (depending on the availability of power packs, nichrome
wires, light bulbs, rheostats, ammeters and voltmeters).
Teacher Notes – C5
1
Integrated Science
Sample SBA Task
Laboratory Report
If students are asked to write a detailed report, the report should include the following items:
1.
Title
2. Aims
3.
Theory/Background (optional)
4.
Apparatus and materials
5.
Design of the experiment
6.
Procedure
7.
Precautions
8.
Results (including data and calculations)
9. Discussion (including sources of error and improvements to be made)
10. Conclusion
11. Questions for further thought (optional)
Remarks
Depending on the ability of the students, there may be variations for this investigation, such
as:
1.
for high-achieving students, inform them of the purpose of this investigation and
provide them with a list of apparatus (but circuit diagrams are NOT provided); ask them
to suggest the set-up and procedure for the investigation;
2.
for students of average ability, a detailed worksheet can be provided to guide them step
by step. If students find it difficult to connect circuits according to the circuit diagrams
given, teachers can provide photographs of the set-ups to help them complete the task.
Suggested Solutions to Questions for Further Thought
1.
You are advised NOT to allow a large current to flow through the nichrome wire when
performing the Part A experiment. Explain why.
A conductor no longer follows Ohm’s law when its temperature becomes high due to a
large current flow. Using a large current in Part A will heat up the nichrome wire and
the wire will not obey Ohm’s law.
2.
Explain the results obtained in Part B using the particle theory.
The atoms in a conductor vibrate more vigorously when the temperature of the
conductor becomes higher and this hinders the flow of electrons. Therefore, the
resistance becomes greater as the temperature increases.
3.
Find out if there are any other conductors that do not follow Ohm’s law.
Graphite and semiconductors are examples of non-ohmic conductors.
Teacher Notes – C5
2
Integrated Science
Sample SBA Task
References
1.
2.
3.
http://en.wikipedia.org/wiki/Electrical_conductor
http://en.wikipedia.org/wiki/Nichrome
http://en.wikipedia.org/wiki/Light_bulb
Teacher Notes – C5
3
Integrated Science
Sample SBA Task
Suggested Mark Allocation
Area A (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Competence in connecting circuits

correct wiring of positive and negative
terminals of ammeter and voltmeter

correct series or parallel connections of
ammeter and voltmeter
Measurement techniques

current is gradually increased at suitable
intervals

measurements are taken with a precision within
that of the ammeter and voltmeter
Data collecting and recording

collecting adequate number of ammeter and
voltmeter readings

keeping a record of the data in an appropriate
way
Safety measures taken

small current (for Part A) / small voltage (for
Part B) is used at the start of the experiment

a large current is NOT used throughout the
experiment
Working efficiently and neatly
TOTAL:
Teacher Notes – C5
4
2
Integrated Science
Sample SBA Task
Area B (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Presentation of results

making appropriate use of table and graph to
present data

recording readings accurately (in appropriate
units)
Plotting of graphs

voltage (as the y-axis) against current (as the
x-axis) and suitable scale for the graphs

correct shape of graphs
Interpretation of results


comparing the graphs
explanations for the different shapes of graphs
Drawing meaningful conclusions
Evaluation of experimental procedure

discussion of the sources of error

suggestions for improvement
TOTAL:
Teacher Notes – C5
5
2
Integrated Science
Sample SBA Task
Module C6: Balance in Nature
Composting bioreactor
Teacher Notes
Composting is the aerobic decomposition of organic matter such as leaves, grass and food
scraps by various organisms. The compost that results is a valuable product that can be used
to enrich the soil for plant growth. Quality compost can be obtained from a proper mix of
‘carbon-rich’ and ‘nitrogen-rich’ waste with adequate amounts of moisture, oxygen and time.
Contrary to large scale compost piles, bioreactors built from soda bottles are small and
inexpensive systems. This small system allows students to design and carry out
individualised investigation, to compare the effect of different types of compost materials,
particle size and moisture content of the materials on compost temperature.
In this activity, students are required to design experiments using soda bottle bioreactors,
change factors in the bioreactor and track the temperature changes. They are expected to
develop skills in making close observations and measurements, careful recording and
analysing data, constructing data tables and graphs, and in presenting results. After the
activity, students should have a better understanding of the composting process and the
benefits of composting.
Curriculum Link
C6: Balance in Nature
6.3
The important role of decomposers in the cycling of materials
Pre-laboratory Preparation
1.
2.
Ask students to search for information on composting.
Ask students to devise plans to compare the effect of factors on compost temperature
using home-made soda bottle bioreactors, and review the design of their plans before
proceeding.
Pre-laboratory Talk
1.
2.
3.
4.
5.
Conduct a brief revision on composting.
Lead a class discussion about the factors that affect the success of a composting system.
Show the soda bottle bioreactor and explain briefly how it can be built.
Draw students’ attention to the safe handling of cutter, scissors and nail.
Remind students of health and safety issues related to the handling of compost
materials.
Teacher Notes – C6
1
Integrated Science
Sample SBA Task
Time Required
Pre-laboratory talk: 15 minutes
Experiment: 50 minutes for Parts A and B
3 weeks for Parts C and D
Grouping
Put two to three students in a group. Each group is required to work on one factor and follow
the progress of the compost for three weeks. Data collected from different groups will be
pooled together and used in writing the laboratory report.
Technician Notes
Holes in the side of the bottle can be made by carefully heating a nail and using it to melt
through the plastic.
Dial / digital thermometer with stem long enough to reach down into the centre of the
compost should be employed.
If possible, a datalogging interface should be provided for students to monitor the
temperature change of the bioreactor.
To prevent any possibility of odour problems, students may be asked to vent the bioreactor
through a window using flexible tubing.
Meat, fish, dairy and cooked food should not be composted as they can attract pests (e.g. flies
and rats).
On the completion of the experiment, students should be asked to transfer all materials from
the bioreactors to another composting container for curing for at least six months before use.
Laboratory Report
If students are asked to write a detailed report, the report should include the following items:
1.
2.
3.
4.
5.
Title
Aims
Theory/Background (optional)
Apparatus and materials
Design of the experiment (To avoid complicated sketch, students can use digital camera
to take a photo of their set-up and include it in the report with clear labeling)
6.
Procedure
7.
Precautions
8. Results (including data and observations)
9.
Discussion (including sources of error and improvements to be made)
10. Conclusion
Teacher Notes – C6
2
Integrated Science
Sample SBA Task
11.
Questions for further thought (optional)
Remarks
Students are not advised to conduct an investigation on the factor of aeration, as it may incur
offensive odour.
In small systems such as soda bottle bioreactors, it is possible that the compost temperature
will reach its peak in less than 24 hours. To avoid missing a possible early peak, use a
continuously recording temperature sensor, or ask the students to measure the temperature
more frequently during the first few days.
Soda bottle bioreactors generally reach temperatures of 40-50 C, somewhat lower than
temperatures achieved in larger composting systems.
With the soda bottle bioreactor, the product may not look like the finished compost from
larger composting systems. With enough time, it is likely that the volume of compost in the
bottle will shrink by 1/2 to 2/3 and that the original materials will no longer be recognisable.
Suggested Solutions to Questions for Further Thought
1.
What are the factors that affect the success of a composting system?
These factors include a right mix of nitrogen-rich materials (e.g. food scraps) and
carbon-rich materials (e.g. autumn leaves and sawdust), moisture content, particle size
of the materials, aeration, and the presence of microorganisms.
2.
How can you tell when the composting process is completed?
The compost will no longer heat up even after stirring and mixing well, and the initial
ingredients are no longer recognisable.
3.
What are the benefits of composting food scraps and garden waste?
It can reduce waste sent to landfill/ reduce pollution from landfill or incinerator/
recycle nutrients back to the soil.
4.
What are the problems and social issues associated with the development of large
community composting projects?
Problems: collection of food scraps and garden waste; odour problems created by the
compost piles
Issues:
choosing appropriate sites for composting facilities; support from local
community/government; making the programme mandatory or voluntary
Teacher Notes – C6
3
Integrated Science
Sample SBA Task
References
1.
2.
3.
http://compost.css.cornell.edu/why.html
http://compost.css.cornell.edu/soda.html
http://www.lcsd.gov.hk/green/en/organic.php
Teacher Notes – C6
4
Integrated Science
Sample SBA Task
Suggested Mark Allocation
Area A (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Competence in handling apparatus such as
thermometer/ datalogging interface
Building a bioreactor


correct set-up
proper filling of compost materials
Measurement techniques

proper location in the bioreactor for
temperature measurement

taking adequate number of temperature
readings
Safety measures taken

handling cutter, scissors and nail safely

wearing gloves when handling compost
materials
Performing experiment in an organised and efficient
way
TOTAL:
Teacher Notes – C6
5
2
Integrated Science
Sample SBA Task
Area B (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Experimental design

independent and dependent variables

assumptions made in the investigation
Presentation of results

making appropriate use of table to present data

recording observation and temperature readings
(in appropriate units) accurately
Plotting of graph

showing compost temperature and ambient
temperature on the same graph

giving appropriate title and labels
Interpretation of results and drawing conclusions

the temperature and decomposition relationship

relevant conclusions of the effect of factors on
composting
Evaluation of experimental procedure

discussion of the sources of error

suggestions for improvement
TOTAL:
Teacher Notes – C6
6
2
Integrated Science
Sample SBA Task
Module C7: Radiation and Us
Ultraviolet (UV) protection of sunglasses
Teacher Notes
This experiment illustrates how science can be applied to check whether the claims made by
manufacturers regarding their sunglasses’ providing protection from ultraviolet radiation are
valid. The investigation can be conducted either inside a laboratory or outdoors under direct
sunlight. Students should be able to distinguish among independent variables, dependent
variables and control variables while planning the experiment. They can also develop skills in
using a datalogger to collect data instantly. It is anticipated that students will apply the
concepts/principles learnt to make informed decisions should they need to buy a pair of
sunglasses.
Curriculum Link
C7: Radiation and Us
7.2 EM radiation as a carrier of energy
Pre-laboratory Preparation
1.
2.
Ask students to browse the websites provided on the handout for background
information and to read the manuals of the UV sensor and UV lamp before the
experiment.
Ask students to collect different types of sunglasses for conducting the experiment.
Pre-laboratory Talk
1.
2.
3.
4.
5.
Remind students that there is no standard set-up for the investigation. They can design
an experiment that is conducted either outdoors or inside the laboratory.
Ask students to sketch the set-up of their design to help illustrate the experimental
procedure.
Remind students NOT to look directly at the UV lamp or the sun.
Remind students that several readings are required for each trial.
Tell students that they may need to convert the raw data in a suitable way to enable
meaningful interpretation.
Time Required
Pre-laboratory talk: 10 minutes
Experimental design: 20 minutes
Conducting experiment: 50 minutes
Teacher Notes – C7
1
Integrated Science
Sample SBA Task
Grouping
Put two to four students in a group (depending on the availability of UV sensors, UV lamps
and datalogging interfaces).
Technician Notes
Not all UV sensors measure the intensity of both UVA and UVB bands. The manual of the
UV sensors should be consulted.
Laboratory Report
If students are asked to write a detailed report, the report should include the following items:
1.
2.
3.
4.
5.
Title
Aims
Theory/Background (optional)
Apparatus and materials
Design of the experiment (Students can use digital camera to take a photo of their set-up
and include it in the report with clear labeling.)
6.
Procedure
7.
Precautions
8.
Results (including data and calculations)
9. Discussion (including sources of error and improvements to be made)
10. Conclusion
11. Questions for further thought (optional)
Remarks
Students should be able to identify:
1.
2.
3.
the independent variable – different types of sunglasses (e.g. different coatings,
different colours of lenses, etc.);
the dependent variable – intensity of UV radiation to be measured; and
the control variables –

distance between UV sensor and UV lamp;

background UV radiation.
While planning the experiment, students should be able to suggest the necessary precautions
such as:
1.
2.
3.
4.
5.
the lenses of sunglasses should be clean and dry;
the front side of the lenses (i.e. the side with coating) should face the UV lamp;
the UV sensor and UV lamp should be kept at a fixed distance;
the UV sensor and UV lamp should be aligned directly at the same level;
the set-up should be free from background UV radiation if the experiment is to be
conducted inside the laboratory.
Teacher Notes – C7
2
Integrated Science
Sample SBA Task
Suggested Solutions to Questions for Further Thought
1.
Is it better to carry out this experiment outdoors under direct sunlight?
It is more authentic to carry out this experiment under direct sunlight. However, there
are factors that affect the measurement such as the position of the sun and the presence
of moving clouds. These factors cannot be controlled easily.
2.
Is it more desirable to carry out this experiment inside the laboratory with sunlight
being blocked by blinds or black curtains?
It is easier to carry out the experiment in a controlled environment inside the
laboratory. However, one should note that the UV radiation (frequency and intensity)
emitted by the UV lamp may not be comparable to those of sunlight.
3.
Is it dangerous to wear sunglasses with coloured lenses which do not block UV
radiation effectively? Explain.
The pupil of the eye will dilate in the shade. If one wears sunglasses with coloured
lenses, one’s pupils will dilate and more light rays will enter the eyes. If the coloured
lenses do not block UV radiation effectively, the increased UV radiation entering the
eyes will damage them.
4.
What are the chemicals commonly used in photochromic sunglasses to block UV
radiation?
Silver halides (usually silver chloride).
5.
Is there any relationship between the colour of lenses and their effectiveness at blocking
UV radiation?
There is no relationship between the colour of the lenses of sunglasses and the
effectiveness of blocking UV radiation. It is the coating on the lenses that matters.
Sunglasses with reflective lenses (which look like a silver mirror) are more effective in
blocking UV radiation than sunglasses with dark coloured lenses.
6.
Will you choose sunglasses with glass lenses or plastic lenses if your primary concern is
blocking of UV radiation?
Plastic lenses usually provide better protection as some plastic materials, such as
polycarbonate, can block most UV radiation.
7.
Can you think of any situation, other than being out in strong sunlight that requires
wearing of protective eyewear to protect from UV radiation?
During welding of metals, strong UV radiation of short wavelength will be emitted.
Welders should use a mask/wear goggles that can effectively block UV radiation.
Teacher Notes – C7
3
Integrated Science
Sample SBA Task
8.
How would you modify the experiment to verify the claim made by some
manufacturers that their umbrellas have UV protection?
The set-up is basically the same except that an umbrella is used instead of a pair of
sunglasses. More stands and clamps are needed to fix the umbrella.
References
1.
2.
3.
4.
http://www.weather.gov.hk/publica/gen_pub/uv_e.htm
http://en.wikipedia.org/wiki/Uv
http://en.wikipedia.org/wiki/Sunglasses
http://www.allaboutvision.com/sunglasses/
Teacher Notes – C7
4
Integrated Science
Sample SBA Task
Suggested Mark Allocation
Area A (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Competence in handling UV sensor and datalogging
interface
Measurement techniques

keeping the UV lamp and UV sensor at a fixed
distance

measuring background UV radiation
Data collecting and recording

obtaining adequate number of readings for each
trial

keeping a record of the data in an appropriate
way
Safety measures taken

NOT looking directly at the UV lamp or the sun

switching off the UV lamp after each
measurement
Self-reliance and working efficiently
TOTAL:
Teacher Notes – C7
5
2
Integrated Science
Sample SBA Task
Area B (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Experimental design

independent, dependent and control variables

assumptions made in the investigation
Experimental plan

clear and logical procedure

necessary precautions taken
Presentation of results

making appropriate use of tables to present data

recording readings accurately (in appropriate
units)
Treatment and interpretation of data

converting the raw data into a percentage of the
UV radiation measured without sunglasses

interpreting the results in terms of absorbance
Discussion of findings and drawing conclusions
TOTAL:
Teacher Notes – C7
6
2
Integrated Science
Sample SBA Task
Module C8: From Genes to Life
Extracting DNA from fruits
Teacher Notes
DNA is the genetic material of living organisms and is found in the chromosomes of every
cell. To obtain DNA from living tissues, the cell and nuclear membranes must be disrupted to
release the DNA. In this experiment, students will apply cell disruption and separation
techniques to extract DNA from plant tissues, and then examine the isolated DNA under the
microscope. They will work on strawberry and on one other fruit sample like kiwifruit,
banana or mango. After the activity, students should develop an appreciation of the
importance of DNA extraction and its applications.
Curriculum Link
C8: From Genes to Life
8.1
Genetic information flow that controls life phenomena
8.2
DNA as the genetic material
8.4
Applications of DNA technology
Pre-laboratory Preparation
1.
2.
Ask students to carry out an information search on the roles of DNA in living
organisms and the basic techniques for extracting DNA.
Ask students to carry out an information search on the applications of DNA technology.
Pre-laboratory Talk
1.
2.
3.
4.
5.
6.
Conduct a brief revision on the importance of DNA to life.
Lead a class discussion on how to extract DNA from plant tissues.
Remind students of the proper way of handling a microscope.
Draw students’ attention to the safe handling of knifes.
Remind students of the safety issue related to the use of methylene blue stain.
Emphasise that the procedures should be followed closely since the temperature and
timing are crucial to the experiment.
Time Required
Pre-laboratory talk: 10 minutes
Experiment: 60 minutes
Teacher Notes – C8
1
Integrated Science
Sample SBA Task
Grouping
Put two students in a group.
Technician Notes
The ethanol used should be ice-cold. Place it in a plastic bottle in a freezer about a day before
the experiment. If a freezer is unavailable, put some ice in an insulated container and then
stand the bottle of ethanol in it for several hours before use.
Filter papers with fast flow rate and coarse porosity should be provided so that the time for
filtering in Step A8 can be shortened. Putting two pieces of gauze on a folded filter paper can
make the filtration faster.
Laboratory Report
If students are asked to write a detailed report, the report should include the following items:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Title
Aims
Theory/Background (optional)
Apparatus and materials
Procedure
Precautions
Results (including data and observations)
Discussion (including sources of error and improvements to be made)
Conclusion
Questions for further thought (optional)
Remarks
Fruits that have multiple sets of chromosomes are more suitable for DNA extraction.
Strawberries are octoploid (i.e. they have 8 copies of each chromosome), thus they can
provide remarkable quantities of DNA for extraction.
The four key steps in extracting DNA from fruits are:
1.
Breaking apart of the tissue and cell wall by physical means such as squeezing,
smashing or grinding the fruit sample.
2.
Disrupting the cell and nuclear membranes by detergent present in extraction solution
to release the DNA. (Detergent and the salt solution also help strip away proteins that
are associated with the DNA molecules.)
3.
Filtering the extraction mixture to remove the insoluble cellular fragments.
4.
Separating DNA from other cellular materials by precipitation in a suitable solvent. (By
adding alcohol, DNA precipitates out and collects at the interface of the alcohol and
filtrate layers. The colder the alcohol, the less soluble the DNA will be in it, and the
more DNA will be collected.)
Teacher Notes – C8
2
Integrated Science
Sample SBA Task
The spooled DNA will appear as a transparent, slimy, clotted mass adhering to the bamboo
stick.
If the DNA appears fluffy, most likely it has sheared in the extraction process.
The appearance of the spooled DNA under the microscope:
Low power (50X)
High power (200X)
Suggested Solutions to Questions for Further Thought
1.
Why is it necessary to squeeze and smash the fruit sample in Step A 4?
This is to provide a mechanical breakdown of the cell wall and structure.
2.
The extraction solution used in Step A5 contains detergent. What is the function of the
detergent?
This is to break open the cell and nuclear membranes to release the DNA. The detergent
causes the membranes to break down by dissolving the lipids and proteins of the cell,
and disrupting the bonds that hold the membranes together.
3.
Why should ice-cold ethanol be used in Step A9?
The colder the ethanol, the less soluble the DNA will be in it, thus yielding more visible
clumping of DNA.
4.
Is the DNA extracted in Step A11 pure? What substance(s) might be attached to the
DNA?
No. The white, stringy stuff is a mix of DNA, RNA and proteins
Teacher Notes – C8
3
Integrated Science
Sample SBA Task
5.
Why is DNA extraction important to scientists? State some of its applications.
The extraction of DNA from a cell is often the first step for scientists in studying a gene.
The study can provide information about the genomic DNA. Applications of DNA
extraction include DNA fingerprinting to solve crimes, and genetic engineering to give
an organism specific traits and to produce medicines.
References
1.
2.
http://learn.genetics.utah.edu/content/labs/extraction/
http://www.imb.uq.edu.au/index.html?id=66795
Teacher Notes – C8
4
Integrated Science
Sample SBA Task
Suggested Mark Allocation
Area A (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Preparing the extraction solution

weighing solid correctly

using appropriate apparatus to make solution
Filtration techniques


setting up of filtration apparatus correctly
using folded filter paper
Competence in handling microscope


handling observed sample properly
using correct procedure for viewing sample
under low-power and high-power
Safety measures taken

handling knife safely

handling methylene blue stain safely
Performing experiment in an organised and efficient
way
TOTAL:
Teacher Notes – C8
5
2
Integrated Science
Sample SBA Task
Area B (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Presentation of results for Part A

good recording of the appearance of thread-like
substance in the ethanol layer

good recording of the appearance of the spooled
DNA
Presentation of results for Part B

good recording of the observation of the
residual DNA being stained by methylene blue

appropriate use of drawings to show the
appearance of the stained DNA under
microscope
Interpretation of results

correct inference for the thread-like substance
appeared in the ethanol layer

correct explanation for the spooled DNA
Drawing meaningful conclusions
Evaluation of experimental procedure

discussion of the sources of errors

suggestions for improvement
TOTAL:
Teacher Notes – C8
6
2
Integrated Science
Sample SBA Task
Module E3: Chemistry for World Needs
How cross-linking changes the properties of a polymer?
Teacher Notes
The properties of a polymer can be manipulated by varying its microscopic structures. A
polymer can be made soft and flexible by adding plasticisers. On the other hand,
cross-linking agents can add strength to a polymer and make it more elastic. In this
experiment, students will be adding a cross-linking agent, borax solution, to strengthen a
polymer, polyvinyl alcohol (PVA).
In Part I of the experiment, students will prepare several slime samples by mixing PVA
solution with varied amounts of borax solution which acts as a cross-linking agent. They will
compare the viscosity of the slime samples and find out how the amount of cross-linking
agent affects the properties of a polymer. In Part II, students will study the characteristic
mechanical properties of a slime sample by observing how it behaves when subject to
different external forces.
Curriculum Link
E3
Chemistry for World Needs
3.4
Man-made polymers fit for different purposes
Pre-laboratory Preparation
1.
2.
3.
Ask students to devise a method to compare the viscosity of some viscous materials.
Ask students to carry out an information search on cross-linking.
Ask students to carry out an information search on the characteristic properties of a
slime material.
Pre-laboratory Talk
1.
2.
3.
4.
5.
6.
7.
Explain to students the principles of cross-linking in polymer chemistry, and give
examples of cross-linked polymers used in daily life.
Show students the chemical structure of PVA, and how cross-links are formed in the
presence of borax.
Discuss the applications of PVA in daily life.
Ask students to propose ways of comparing the viscosity of some viscous materials.
Suggest possible ways of recording experimental results and presenting experimental
findings, e.g. keeping a log of the results, taking photographs of the observations,
presenting findings using posters, etc.
Draw students’ attention to the safe handling of borax – students should wash their
hands thoroughly after the experiment.
Remind students to handle the hammer (or mallet) carefully to avoid injury.
Teacher Notes – E3
1
Integrated Science
Sample SBA Task
Time Required
Pre-laboratory talk: 15 minutes
Experiment: 30 minutes for Part I
15 minutes for Part II
Discussion/debriefing: 10 minutes
Grouping
Put two to three students in a group (depending on the availability of apparatus).
Technician Notes
In preparing the 4% PVA solution, slowly add 4 g of PVA to 100 ml of distilled water, which
has been heated to about 80 oC. Keep stirring until the PVA dissolves. Allow the solution to
cool.
Students may need help in preparing the stock solution of borax.
It is advisable to cover the laboratory benches with a disposable plastic table-cloth to
facilitate cleaning up after the session.
Dispose of any slime in the rubbish bin. Do not put it down the drain as it will clog the drain.
Laboratory Report
If students are asked to write a detailed report, the report should include the following items:
1.
Title
2. Aims
3.
Theory/Background (optional)
4.
Apparatus and materials
5.
Design of the experiment
6.
Procedure
7.
Precautions
8. Results (including data and observations)
9.
Discussion (including sources of error and improvements to be made)
10. Conclusion
11. Questions for further thought (optional)
Students can also be asked to present their findings using posters and/or PowerPoint slides.
Teacher Notes – E3
2
Integrated Science
Sample SBA Task
Remarks
In Part I, students should be able to realise that the viscosity of a slime is proportional to the
amount of cross-linking agent added to it. They may also realise that carrying out tests with
samples of the same size and shape is crucial to the comparability of the tests.
In Part II, students carry out tests to study the characteristic mechanical properties of a slime.
They would observe that the slime resists a gentle blow, but breaks apart into small pieces
when hit with a sharp blow. When the slime is pulled quickly, it breaks into two halves
immediately. However, the slime can be stretched into a thin film without breaking if it is
pulled gently and slowly.
Suggested Answers to the Questions
Part I:
1. What happens to the mixture of PVA solution and the borax solution when it is stirred
vigorously?
2. Which slime sample is the most viscous and which one is the least viscous?
3. Why is it necessary to remove excess water and air bubbles from the slimes before
performing the tests?
4. Why is it necessary to have the slime samples for testing made into the same size and
shape?
5. Should we perform the test on a piece of paper instead of the plastic sheet? Explain
briefly.
6. How can we get a better measure of the diameter of the slime?
7. Does the degree of cross-linking of PVA slime increase or decrease with the
concentration of the borax solution added? Explain briefly.
8. Apart from varying the proportion of borax in PVA slime, what other experiments can be
done on the slime to study its viscosity?
1.
What happens to the mixture of PVA solution and the borax solution when it is stirred
vigorously?
The slime sample becomes more viscous. / The viscosity of the mixture increases.
2.
Which slime sample is the most viscous and which one is the least viscous?
The slime sample prepared with 5% borax solution is the most viscous. The one with 1%
borax solution is the least viscous.
3.
Why is it necessary to remove excess water and air bubbles from the slimes before
performing the tests?
To ensure comparability among the tests. Squeezing the excess water out from the
samples is to make sure all the samples have similar water content. Removing the air
bubbles is to make sure the samples are uniform throughout.
4.
Why is it necessary to have the slime samples for testing made into the same size and
shape?
Teacher Notes – E3
3
Integrated Science
Sample SBA Task
To ensure comparability among the tests.
5.
Should we perform the test on a piece of paper instead of the plastic sheet? Explain
briefly.
Plastic sheet is superior to paper for carrying out the viscosity test because plastic sheet
does not absorb water and hence will not change the properties of the slime samples
during the test.
6.
How can we get a better measure of the diameter of the slime?
Place a graph paper below the plastic sheet; read the diameter from the grids of the
graph paper. Read the diameters at 2 perpendicular directions and take the average.
7.
Does the degree of cross-linking of PVA slime increase or decrease with the
concentration of the borax solution added? Explain briefly.
The degree of cross-linking increases as the concentration of borax solution increases.
Borax is a cross-linking agent. More cross-links can be formed with an increased
amount of borax added to the sample.
8.
Apart from varying the proportion of borax in PVA slime, what other experiments can be
done on the slime to study its viscosity?
Compare the viscosity of a slime sample at different temperatures.
Suggestions for Further Investigation
Teachers may ask students to further explore the properties of cross-linked polymers by
carrying out the following activities:

Comparing the viscosity of slime samples prepared from PVA of different
concentrations

Comparing the viscosity of a slime sample at different temperatures

Comparing the properties of other cross-linked polymers such as those prepared by
mixing ‘white glue’ with the appropriate amount of borax

Investigating the mechanical properties of commercial available slimes such as
‘Slime’ toys
Teacher Notes – E3
4
Integrated Science
Sample SBA Task
Suggested Mark Allocation
Area A (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Preparing the stock borax solution

weighing solid correctly

using appropriate techniques in making solution
Preparing the borax solutions of varied
concentrations

adding the correct amount of water

using appropriate apparatus to make solutions
Conducting fair tests to measure the viscosity of the
slime samples

making samples of same size and shape

using same measuring time
Testing the slime sample with an external force

using appropriate set-up for the test

handling hammer (or mallet) when hitting the
sample safely
Working efficiently and neatly
TOTAL:
Teacher Notes – E3
5
2
Integrated Science
Sample SBA Task
Area B (Maximum 10 marks):
Marks
Abilities to be assessed
0
1
Presentation of results for Part I

recording accurately the amount of distilled
water used for dilution

recording accurately the diameter of the slime
Plotting a graph of the diameter of the slime against
the concentration of borax solution

giving appropriate title and labels

drawing an appropriate graph through the data
points
Interpretation of results for Part I

giving the correct/logical inference from the
graph
Presentation of results for Part II

making a good recording of the observations for
hitting the slime sample with a hammer (or
mallet)

making a good recording of the observations for
pulling the slime sample with both hands
Conclusions and suggestions for further
investigations
TOTAL:
Teacher Notes – E3
6
2