& A-Level Science Practical’s will start from Tuesday (15th September
The practical skills
manipulation, measurement and observation, the collection of simple data to an
appropriate accuracy, choosing the right range and distribution of values
presentation of data and observations in a table
analysis, conclusions and evaluation, using and justifying the correct number
of significant figures
plotting of a graph and calculation of a gradient. In the second paper this
involves the use of logarithms and plotting error bars on graphs
estimating the uncertainties in measurements made and identifying the most
significant sources of uncertainty
calculating the uncertainty in the value of a calculated quantity made from two
or more measurements each with their own uncertainty
evaluation of the method involved and suggesting improvements
planning an experiment, including identifying dependent and independent
variables and quantities that remain constant, identifying any risks involved
Developing practical skills
prepares students for studies beyond A Level in physics, engineering or in
physics-dependent vocational courses. Practical’s also help students
develop abilities and skills that are useful in everyday life and encourage
safe practice. These practical skills help to develop attitudes such
as a concern for accuracy and precision, initiative, inventiveness and a spirit
skills are important in employment and go far beyond mere knowledge of facts. A
good practical course also helps to develop an interest in the
subject of physics itself and complements the study of the theory, showing that
scientific theory is ultimately grounded by experiment. The amount of practical apparatus
required does not have to be enormous because working within the resources
available is another useful ability. It’s important to remember that students
can learn a lot from practical work that goes wrong as well as
from experiments that work perfectly every time.
students at A Level may not have had much experience of practical work
and may not consider themselves to be very ‘practical’, but there is no need to
be afraid of simple experiments. Students need practice in setting up simple
apparatus and to be happy in carrying out the experiment by themselves.
When a student has enough experience of simple apparatus then they face the
challenge of writing a method where they must choose the apparatus and method
for themselves. This might be for an experiment that differs from any that they
have previously seen and shows their inventiveness and initiative.
may also believe practical work to be a mathematical exercise where
there is a right and a wrong answer. This is not the case. Every reading has an
inherent uncertainty and students need to be happy to estimate uncertainties in
simple quantities, such as the measurement of length and time by either
repeating readings or taking the smallest scale reading on the instrument used.
They also need to realize that the uncertainty is only an estimate and is
itself not exactly known.
are a few mathematical challenges, particularly for those not studying
mathematics at A Level. These include the use of logarithms and combining
uncertainties, where a real familiarity with percentages is a useful skill.
However, the average student can learn the necessary skills with a reasonable
amount of application.
Think actively about every topic. Do you understand what is going on? If not,
then ask a question.
Know how to estimate uncertainty as the smallest scale division or, better,
half the range in the readings.
After every experiment write down:
the steps that you actually took during the experiment
– whether each quantity was dependent, independent or kept constant
– major difficulties
Realize that readings in a table are measured, usually, to the same precision,
i.e. to the same number of decimal places, but that calculated quantities
should be given to the smallest number of significant figures in the quantities
used in the calculation.
Take care when plotting graphs.
does your graph cover half the page horizontally and vertically?
– does it have units on both axes?
– check your points are accurate
– use a long ruler when drawing a straight line
– show your working in finding the gradient
Remember that practical work is important; it is a component of your
examinations. Therefore, make the most of whatever practical experience
that you are given and don’t think of it as relaxation time away from theory
Remember that practical work is related to the rest of the syllabus.
If you are not sure why you are doing the practical – ask your
teacher to explain. When you are told that you will be doing a practical investigation,
write down what you think are the aims of the practical work and what
you hope to get from it.
If you have a practical partner, then agree responsibilities. For
example, if you are measuring the rate of a reaction by following the change in
the volume of gas produced, one of you can measure the time and help countdown
to the next reading, while your partner can read the volume.
If you are going to do an assessed practical, then ask your teacher what
criteria she or he is going to use when allocating the marks.
Try and maintain a good balance between your awareness of safety and a
confident use of the apparatus. You should by now know how to use a Bunsen
burner safely and the difference between gentle heating and strong heating,
even some advanced level students think that gentle heating involves a yellow
Bunsen burner flame. The has
a chapter on basic techniques. If this textbook is available, then take a look
at this chapter.
they can embark on AS & A Level practical work with confidence,
students should be familiar with the use of a typical school laboratory. This
includes things such as balances, measuring cylinders, beakers, pipettes (or
syringes), heating apparatus and thermometers. It is also important that students
know how to work safely when carrying out practical work.
knowledge of basic biochemical tests such as the tests for starch, glucose,
protein and lipids is useful as these are often revisited at AS & A
Level. There is also an assumption that students are aware of simple
tests from Cambridge IGCSE™ chemistry, such as using universal indicator paper
and testing for using limewater to test for carbon dioxide gas. These chemical
tests are often used when carrying out practicals at AS and A Level
should also understand how to plan valid experiments with standardized
variables and repeats. They should also know how to draw results tables that
display data effectively. Evaluating the design of simple experiments, such as recognizing
the level of accuracy of equipment is also a useful skill to reinforce before
AS & A Level. All these skills help to provide a good foundation upon which
biology experiments, results can often be unpredictable! Living organisms often
do not respond in the ways that we expect. For example, a piece of pond weed in
an investigation into the effect of light intensity, may not photosynthesis due
to several reasons. Students need to be patient, accept that all results are
valid and explore the reasons for results not being as expected. Many students
think that getting unexpected results is essentially the mark of a bad
experiment – in reality, getting the ‘wrong results’ can be a learning
experience in itself. Students should also not be scared to ‘have a go’ and be
encouraged to try again if something did not seem to work first time.
Be confident and keep trying even if a technique is difficult
2) Don’t expect results to always go the way you planned – remember that living
organisms can be very different to one another
3) Work safely – always wear eye protection and risk assess everything
4) Be organized – keep all your equipment tidy on your bench
5) Enjoy practical work – it is your opportunity to apply your
knowledge to the real thing
Science Practical’s will start from Tuesday
(15th September 2020) at
GreenHall Academy Gulberg Campus.
Academy Gulberg Campus:
& Most Reputed Evening Coaching Network of O/A Level & Entry Tests