Uploaded by Tran Huy

moam.info igcse-coordinated-sciences-0654-combined-science-0 59cc8a591723ddab3bbdfff3

advertisement
Yew Chung International School of Shanghai – Gubei Campus
Science Department
IGCSE
Coordinated Sciences (0654)
&
Combined Science (0653)
Guide for students
Name________________
Albert Einstein
"Not everything that counts can be counted, and not everything that can be counted counts."
(Sign hanging in Einstein's office at Princeton)
-2-
Contents
Useful Websites
5
IGCSE Course Overview
6
Course Assessment
7
Plagiarism
8
Referencing
8
YCIS Science Safety Rules
11
Assessment & Grade Thresholds
12
Guide to Writing Experimental Reports
13
IGCSE Example Lab 1: Pendulum Investigation
18
Symbols, Units and Definitions of Physical Quantities
35
Periodic Table
36
Notes for use in Qualitative Analysis
37
Glossary of Terms Used in Science Papers
38
Studying Effectively
39
Glossary
40
-3-
Ernest Rutherford
Niels Bohr
“If your result needs a statistician then you should
design a better experiment”
“An expert is a man who has made all the
mistakes which can be made in a very narrow
field”
Sir Isaac Newton
Dorothy Hodgkin
“If I have ever made any valuable discoveries, it
has been due more to patient attention, than to
any other talent”
“I was captured for life by chemistry and by
crystals”
Dmitri Mendeleev
Gregor Mendel
"The elements, if arranged according to their
atomic weights, exhibit an apparent periodicity of
properties."
“The value and utility of any experiment are
determined by the fitness of the material to the
purpose for which it is used, and thus in the case
before us it cannot be immaterial what plants are
subjected to experiment and in what manner such
experiment is conducted.”
-4-
Useful Websites
1. http://www.cambridgestudents.org.uk
The official CIE website which contains: Past papers, revision tips, study checklists,
exam advice, online competitions.
2. http://www.rsc.org/education/teachers/learnnet/alchemy/index2.htm
From the RSC - good for resources including videos on industrial process
3. http://www.rsc.org/chemsoc/timeline//pages/timeline.html
4. http://www.s-cool.co.uk/default.asp
5. http://www.bbc.co.uk/schools/gcsebitesize/science/
BBC Bitesize Revsion → general revision → tests
6. http://www.channel4.com/science/
Very good site; also has a question facility called "Ask an Expert"!
-5-
IGCSE Course Overview
Both Coordinated Sciences and Combined Science cover all three sciences: Biology, Chemistry and Physics.
One third of each course is spent on each science. Both courses use the same textbooks and every year 10
student and every year 11 student will be issued with both books at the start of the year. The text books are:
Balanced Science 1 (ISBN 0521599792) and Balanced Science 2 (ISBN 0521599806) published by
Cambridge University Press. Other texts are used to support these text books.
The units of work in years 10 & 11 cover all areas needed to progress to an advanced course of study (IB
Diploma) in one of the sciences. All students are taught the extended/supplement syllabus for the duration of
the course.
Year 11
Year 10
Biology
Chemistry
Physics
B1 – The principles of biological
classification and the diversity of
organisms
B2 – Cellular organization and
function
B3 – Support and movement
B4 – Photosynthesis
B5 – Gaseous exchange in
animals
B6 – Transport systems
B7 – Respiration
B8 – Diet and health
B9 – Digestion
B10 – Responding to changes in
the environment
B11 – Homeostasis
C1 – The elements of chemistry
C2 – Classifying the elements
C3 – Petrochemicals
C4 – Chemicals from plants
C5 – Materials and structures
C6 – Oxidation and reduction
C7 – Ions and electrolysis
C8 – Solvents and solutions
C16 – Metals and alloys
C17 – Atoms, bonding and the
periodic table
P1 – The strength of solids
P2 – Particles in motion
P3 – Motion
P4 – Force and motion
P5 – Energy transfer
P6 – Transferring energy by
heating
P7 – Using electricity
P8 – Energy and electricity
P9 – Waves
P10 – Light and sound
P11 – Making use of waves
B12 – Reproduction
B13 – Human reproduction
B14 – Inheritance
B15 – Evolution
B16 – Organisms in their
environment
B17 – Cycles and the effects of
humans on their environment
C9 – Acids and alkalis
C10 – Soil, rocks and reaction
rates
C11 – Fertilizers
C12 – Dyes and drugs
C13 – Colloids
C14– Fuels
C15 – Batteries
P12 – Kinetic energy and
momentum
P13 – Gravity
P14 – Magnetism and electricity
P15 – Communication
P16 – Electrons
P17 – Radioactivity
P18 –Energy resources
P19 –Energy distribution
P20 –Electronics
-6-
Course Assessment
Both courses last for two years. Students are continuously assessed through coursework, homework,
experimental work and end of unit tests. The final examinations at the end of year 11 are externally assessed.
All students will sit three exams: Paper 1 and Paper 2 OR 3, and Paper 6.
All students sit these two papers:
Paper 1 (multiple choice)
• 40 multiple choice questions based on core
material.
• 45 minutes.
• 40 marks total.
• Worth 30% of the final grade.
• Period table is included.
• Calculators are allowed.
• Dictionaries of any sort (definition/treanslation
or paper/electronic) are NOT allowed.
and
Paper 6 (alternative to practical)
• Short answer questions based on
experimental work.
• 1 hour
• 60 marks total.
• Worth 20% of the final grade.
• Paper translation dictionaries only are
allowed.
• Calculators are allowed.
• Periodic table is NOT attached to the exam
paper (not allowed).
All students sit one of these papers (i.e. paper 2
OR paper 3). Which paper students sit is based on
grades achieved and is determined near the end of
the course.
Paper 2 (short answer)
• Short answer questions on core material.
• 1 hour 15 minutes (Combined) OR 2 hours
(Coordinated).
• 100 marks total.
• Worth 50% of the final grade.
• Paper translation dictionaries only are
allowed.
• Calculators are allowed.
or
Paper 3 (short answer)
• Short answer questions on extended material
• 1 hour 15 minutes (Combined) OR 2 hours
(Coordinated).
• 100 marks total.
• Worth 50% of the final grade.
• Paper translation dictionaries only are
allowed.
• Calculators are allowed.
• Periodic table is included.
-7-
9th April 2008
Dear Parents,
I write to you on a serious matter. The issue of plagiarism is becoming more common across Schools
worldwide and I think it would be helpful if I set out what plagiarism is and why it is so important to
avoid.
A common definition of plagiarism is:
“Plagiarism is the practice of claiming or implying original authorship of (or incorporating material
from) someone else's written or creative work, in whole or in part, into one's own without adequate
acknowledgement. Unlike cases of forgery (in which the authenticity of the writing, document, or
some other kind of object itself is in question), plagiarism is concerned with the issue of false
attribution.” (Wikipedia 2008)
Plagiarism is essentially cheating. If a pupil uses someone else’s work without acknowledgement, he
or she is implying that it is their own work – and that is not the case. This is not a minor matter.
With the increased use of the internet and the increasing assumption by some students that their work
must be ‘perfect’, a number of students simply search for content on the Internet and then ‘cut and
paste’ paragraphs or whole articles which they then hand in as either their own work or as ‘research’.
This practice is not acceptable.
There is nothing wrong with using the comments of others or the ideas of others in your own work –
but these must be properly acknowledged. There are a number of ways in doing this, and I cite a
common one below:
“God’s Word does more than give being. It sets limits and provides life. Apple seeds do not produce plum trees. They
grow up into apple trees and they do this at the Word of the Lord.”1
If you look at the bottom of this page, you can see that the above quote is identified by
the title of the book
the author
the publisher and date of publication
the page number
If you look at the beginning of my letter there is an alternative option of placing the source in brackets after the quote.
Whatever choice a pupil makes, they should be consistent. A useful test is to check whether the information provided is
enough for a reader to check the source without difficulty.
Pupils often make two false assumptions when they think they need to plagiarize:
The work submitted must be perfect. This is not the case. Homework or research should reflect the pupil’s best effort, but
does not need to be perfect to gain high marks.
A pupil has left it too late to write something themselves and decides that handing in a piece copied from the Internet is
better than handing in no homework at all. This is not the case. Plagiarism creates a problem that is much larger than an
apology to the teacher for late homework.
If a pupil does submit plagiarized work, it is very likely to be detected. This is for the following reasons:
the work might use language which is more advanced than the pupil normally uses in their work
the ideas or concepts are too complex for the pupil or explained in a way that is different to the way the pupil
normally explains things
the question is not properly addressed and there is a lot of irrelevant material included
a number of students might submit the same piece of work
Schools also have access to an additional software system to which work is routinely submitted. Pupils should also be
aware that teachers (and Co-Principals) have a great deal of experience in spotting plagiarism.
1
Reclaiming the Future of Christian Education, A.E.Greene, ACSI 1998, page 83
-8-
The penalties for plagiarism are severe. At a minimum, the work in question is not marked and given a zero grade. Other
sanctions may also apply. If plagiarism is attempted in work submitted for an examination subject (such as at IGCSE or
the IB), penalties include the loss of an entire examination subject (and in the case of the IB, the loss of the Diploma). In
examination years, penalties can also be financial as the School needs to move a pupil from one examination unit to
another and this cost will be passed on to parents.
Plagiarism in later life (at university or in a profession) is not a risk worth taking either. Students lose their degrees,
writers have had to withdraw books from circulation and even governments have had to apologize. Politicians have had to
abandon their political careers when they were found to be using words taken from the speeches of others without
acknowledgement.
There is no need for plagiarism. We have been given the ability to think, decide and write for ourselves. Let us use these
abilities.
Yours,
Dr Barkei
Co-Principal
-9-
Marie Curie
“Nothing in life is to be feared. It is only to be understood.”
- 10 -
YCIS Science Safety Rules
Gubei Campus
As part of the IGCSE Science Courses offered at YCIS you will be working in the laboratories regularly. Many
laboratory activities require the use of hazardous chemicals and materials. To ensure that work in laboratories
is done in a safe environment, the following rules must be followed:
1.
You must follow all safety instructions stated by your teacher. This involves wearing safety
glasses/goggles and lab coats. Sometimes additional safety requirements will be required. Long hair must
be tied back and no open footware is allowed.
2.
You must only do the experiment/procedure that you have been instructed to do. Do not touch any other
objects/equipment/chemicals.
3.
Books, purses, backpacks, etc. must be stored in an area designated by your treacher.
4.
Do not do the following in a laboratory EVER: eat food, drink beverages, chew gum or run.
5.
Work areas and equipment should be kept clean and tidy at all times. Bring only materials specified by
your instructor to the work area.
6.
Dispose of all waste materials in an appropriate manner as designated by your teacher. This means do
not pour anything down the sink unless you are told to by your teacher. Do not return chemicals to their
original containers unless you are specifically instructed to do so.
7.
Read chemical labels very carefully. Make sure that you have the correct substance in the correct
concentration. Check the label twice before removing any of the contents. Follow the instructor’s safety
instructions for handling hazardous materials.
8.
Never take chemicals, supplies, specimens, or equipment out of the laboratory without the knowledge and
consent of your teacher.
9.
Never enter a laboratory without the supervision of a teacher.
10. Never point the open end of a test tube being heated at yourself or others.
11. Always protect the balances/scales when weighing chemicals.
12. If you spill material clean it up immediately.
13. Used glassware goes in the dirty glassware container located in each laboratory.
14. Know the locations of fire extinguisher, fire blanket, eyewash, safety shower, and first aid kit.
Accidents and Injuries
1.
Report any accident (spill, breakage, etc.) or injury (cut, burn, etc.) to your teacher immediately.
2.
Water spills on the floor need to be cleaned up immediately.
3.
If a chemical should splash in your eye(s) or on your skin, immediately flush with running water from the
eye wash/safety shower for at least 15 minutes. Notify your teacher immediately. You must also see the
nurse (on the ground floor of A block).
4.
Treat burns immediately by putting the burned area under cold water. You must also see the nurse (on
the ground floor of A block).
- 11 -
IGCSE Experimental Programme
All students are required to complete IGCSE experiment programme. This is structured to cover the scientific
theory and techniques required by the syllabus. It is also designed to prepare students for the programmes of
study at IB level. The laboratory work completed in years 10 and 11 counts for 20% of the final grade. Students
complete two types of experimental reports: short answer and formally assessed experiments.
Formally assessed reports are marked on four possible skill areas:
1.
2.
3.
4.
Design (D) – Designing/planning the experiment
Data Collection and Processing (DCP) – Collecting data in tables and presenting it as graphs
Conclusion and Evaluation (CE) – Explaining and evaluating the results of your experiment
Manipulative Skills (MS) – Working safety and as part of a team in the laboratory
You could be assessed on all four criteria or one or two or three of the criteria. Your teacher will advise you
prior to each lab which aspect you will be assessed on.
Grade Thresholds – Coordinated Sciences
Grade
A*
A
B
C
D
E
F
%
91-100
80-90
68-79
50-67
38-49
26-37
0-25
Report Comment
Excellent
Very good
Good
Satisfactory
Mediocre
Poor
Very poor
Grade
A*
A
B
C
D
E
F
%
85-100
70-84
55-69
40-54
30-39
20-29
0-19
Report Comment
Excellent
Very good
Good
Satisfactory
Mediocre
Poor
Very poor
Grade Thresholds – Combined
- 12 -
Guide to Writing Experimental Reports
Design (D)
1 – Defining
the problem
and selecting
the variables
Total:
/16
Formulate a focused research question (RQ).
The research question must be short and concise (one sentence). It should contain the
dependent and the independent variables. It should be written after the words: “Research
Question”
/2
Gives a qualitative hypothesis and justifies it with scientific reasoning and a calculation if
appropriate.
The hypothesis should be written after the words: “Hypothesis”. Below this comes the
scientific reasoning and calculation if appropriate. At the minimum, your report should
contain one internet reference and one book reference.
/2
Identifies the key factors (variables) that should be varied or controlled.
There are three classes of variables: independent (the one you change), dependent (the
one you measure) and the control variables (the ones kept constant by you or are
assumed to be constant such as external pressure on a calm day or the force of gravity).
In this section you need to overview the possible investigations and then decide on the
variables you will change (independent) and measure (dependent). See selecting variables
below.
2 – Selecting
variables
3–
Developing a
method for
collection of
data
States the independent variable (the one you
change).
States the dependant variable (the one you
measure).
States the controlled variable(s) (the one(s)
that must be kept constant).
These can be grouped together and listed
with bullet points like this:
Independent variable: Length of string
Dependent variable: Time taken for
one complete swing
Constant variables: Size of swing,
mass, temperature, air resistance,
force due to gravity
/2
/1
/1
/2
Selects and names appropriate apparatus and materials needed.
For glassware, all sizes must be listed. For chemicals, all concentrations/masses must be
listed. You must also list the form of the chemical (for example if it is magnesium powder
or magnesium strip). These should be listed in bullet point form. You can also show the
apparatus that you intend to use using a labeled diagram. Remember to put a title on this.
/2
Designs a method that allows for the effective control of the variables.
This is the method of the experiment. What will you do first and second and so on. This
should be done using bullet points. Be sure to add a sentence noting that when the
independent variable is changed, all other variables are held constant.
/2
Designs a method that allows for the collection of sufficient relevant data.
To gain full marks for this criterion you need to state that three trials will be done and the
results averaged to give the final number for the measurement. Repeats are two or more
measurements of the dependent variable, with the same level of the independent variable.
Repeats help you to assess whether your results are reliable or not.
- 13 -
/2
Data Collection and Processing (DCP)
1 – Collect
and organise
raw data
Total:
/18
Record all raw data (qualitative and/or quantitative)
Usually the data that you collect will be quantitative - measurements with the correct
units. You should record these measurements as accurately as possible during your
experiment. This is usually done manually using a results table on paper. If working
with a partner, do not rely on them to record the results - do it yourself. After the
experiment, you should draw up a clear and accurate results table. Show every result
that you obtained, not just the mean results. Repeat results should be numbered. The
column headings on results table should show both the quantity being measured with
the correct units.
/2
Sometimes your data will be qualitative - drawings of structures, colour changes or
other observations. Drawings should be large, with sharp lines and labels or annotation
to interpret the structures shown. Measure the size of the specimen and the drawing
and calculate the magnification. Remember to include a title for both drawings and
results tables.
Presents raw data clearly.
/2
This means that data is collected in a table and the table is easy to read.
Uses correct headings, units and significant figures.
/2
2 – Processing
raw data
Makes the correct calculations on the raw data.
The results that are collected during an experiment are called raw data. It is usually
necessary to process this raw data in some way. This might involve calculating mean
results, or performing a statistical test on the data. It might involve drawing a graph or
displaying the data in some other way. If you are drawing a graph, remember to put the
independent variable on the x~axis and the dependent variable on the y-axis. Join the
points with a curve or straight lines, depending on whether you know where intervening
points would have been or not. Check that you have labelled both of the axes with the
quantity and the units, for example, mass (grams). If your raw data consisted of
drawings, you can process them by constructing a diagram to show significant features
of the structure.
/2
Pays attention to units, significant figures and decimal places in final answer.
/2
Extracts relevant data from the graph if drawn (intercept, gradient etc.).
/2
This must be indicated on the graph.
3 – Presenting
processed
data
Presents the processed data appropriately (correct choice of graph, bar chart etc.).
Chooses an appropriate scale and plots points/displays processed data correctly/adds
trendline.
Uses correct labels, units and line of best fit drawn (if graph chosen).
- 14 -
/2
/2
/2
Conclusion and Evaluation (CE)
1 – Concluding
Total:
States a valid conclusion which relates to the
initial problem or hypothesis
What trends are shown by the data?
What is the explanation for the observed
differences or relationships?
Identifies trend and patterns in the results
How does the data compare with data from
similar experiments in textbooks or
scientific journals?
Explains the results scientifically using
relevant secondary sources.
/18
/2
/2
What conclusions can be drawn from the
investigation? (if any!)
As in Design (aspect 1 – see above) you
should use a reference here giving a
literature value for the result so you can
calculate the percentage error.
2 – Evaluating
Comments on the reliability and accuracy of
the results obtained
This section should be listed under the
title: “Evaluation”)
/2
/2
You need to address the points on the left:
Consider the following:
Identifies weaknesses and errors in the
procedure
Are there any results that did not fit in with
the rest? These are called anomalous
results.
/2
Were there any errors made during the
experiment that explain the anomalous
results?
Distinguish between systematic and
random error. Your main focus should be
on systematic errors (these are errors that
are consistently the same e.g. the balance
always reads 0.6g too low). For systematic
error, indicate direction and give an
estimate for the magnitude of effect on
final result, where possible.
Identifies anomalous results and tries to
explain them
3–
Improvements
Suggests improvements related to stated
areas of weakness
Proposes further improvements to increase
reliability of results
Suggests further work that would give more
evidence for the conclusion or extend the
investigation.
How successfully did the method used in
the experiment generate reliable results?
You can often decide whether results are
reliable or not by how close repeats are to
each other.
- 15 -
What were the main weaknesses in
the investigation?
What could be done to make genuine
improvements to the investigation, if it
was done again?
/2
/2
/2
/2
Manipulative (MS)
1 – Technique
2 – Instructions
3 – Teamwork
Total:
Is competent in the use of the technique(s)
and the equipment, and pays attention to
safety issues.
Follows the instructions accurately
Is motivated and completes the experiment &
collaborates with others, recognising their
needs, in order to complete the task.
If you have done enough practical work in
Science, your manipulative skills should
be excellent. You probably will not need
the following reminders!
•
•
•
- 16 -
Study instructions carefully
before starting work so that you
know what you are doing.
Be sensible about asking for help
from your teacher. Try to work
out what to do yourself. Use your
own initiative to decide how to
modify a procedure yourself
when necessary. But if you have
not been given full enough
instructions or are worried about
the safety of the procedure, ask
for help.Make sure that you know
about any potential risks in the
procedure that you are following.
Work in a careful and systematic
way - arrange your apparatus
tidily and do not waste time, but
work without rushing.
/6
/2
/2
/2
Sir Charles Darwin
“I am turned into a sort of machine for observing facts and grinding out conclusions.”
- 17 -
17th December 2002
Lisa Simpson
IGCSE Example Lab 1
Pendulum Investigation
Experiment Title – Investigate how the length of a simple pendulum affects the time for a complete swing.
Design (D)
Research Question – How does the time taken for one complete swing vary with the length of string for a free
swinging pendulum?
Hypothesis – As they string increases in length the time taken for one complete swing will increase.
The diagram shows the arcs through which two pendulums swing. The longer one is twice the
length of the shorter one. The shorter pendulum is always at a steeper angle than the longer
arc, and always above it. The shorter pendulum has the most gravitational potential energy at
the top of the swing because it is higher. This means the kinetic energy and hence speed
through the centre will also be greater than for the red pendulum. From previous experiments I
know that for trolleys running freely down a ramp that the bigger the angle of the ramp the
bigger the acceleration of the trolley. This same principle can be applied to the falling
pendulums. The steeper the arc the bigger the acceleration of the pendulum will be. A bigger
acceleration means a shorter time for each swing. Unlike a ramp the arc of swing is not a
straight line. The arc has the steepest gradient at the top and is flat when it reaches the middle.
The acceleration of the bob will thus decrease from a maximum at the top of the swing to zero
at the centre.
Theory – When the pendulum is at the top of its swing it is momentarily stationary. It has zero kinetic energy
and maximum gravitational potential energy. As the pendulum falls the potential energy is transferred to kinetic
energy. The speed increases as the pendulum falls and reaches a maximum at the bottom of the swing. Here
the speed and kinetic energy are a maximum, and the potential energy is a minimum. As the pendulum rises
the kinetic energy is transferred back to potential energy. The speed of the pendulum decreases and falls to
zero as it reaches the top of its swing, with the potential energy a maximum again. A small amount of energy is
lost due to air resistance as the pendulum swings. This means each swing is slightly smaller than the one
before.
Variables
Independent Variable: Length of string
Dependant Variable: Time of swing
Control Variables: Size of swing, mass attached to string, air resistance, gravity
Method
1. Set up the experiment as shown in the diagram below – use a plasticine bob of mass 25g
2. Start with string of length 20 cm
3. Pull pendulum slightly to the side (about 10 cm) and release
4. Time 20 complete oscillations and enter into results table
5. Increase length of string by 20 cm
6. Continue until string is 160 cm long
Clamp
Equipment List
1. Cotton
2. Plasticine
3. Metre rulers
4. Digital stopwatch
5. Retort stand and clamp
String
Bob
- 18 -
Table
Data Collection and Processing (DCP)
Length √Length Number Time
(cm) (√cm) of swings for N swings (s)
N
Average time Average time
N swings
1 swing (s)
5.0
2.24
50
22.84 22.91 22.88 22.88
0.46
10.0
3.16
50
32.16 32
32.19 32.20
0.64
20.0
4.47
20
18.10 18.06 18.03 18.06
0.90
40.0
6.32
20
25.40 25.47 25.34 25.40
1.27
60.0
7.75
20
31.09 31.08 31.06 31.08
1.55
80.0
8.94
20
35.94 35.90 35.91 35.92
1.80
100.0 10
20
40.12 40.08 40.09 40.10
2.00
120.0 10.95
20
43.97 43.97 43.90 43.95
2.20
140.0 11.83
20
47.31 47.37 47.44 47.37
2.37
160.0 12.65
20
50.72 50.75 50.75 50.74
2.54
The graph on the left shows that the time taken for each swing increases as the length increases but the
relationship is not linear. The rate of increase of time per swing decreases as the length increases.
The graph on the right shows the linear relationship between the time taken for each swing and the
square-root of the pendulum length.
The equation for a straight line through the origin is; y = mx
The gradient m measured from the graph = 2.5÷12.5 = 0.20
If T is the time for one swing in seconds, and L is the length in centimetres, the equation for the line can be
written as; T = 0.20√L
- 19 -
Conclusion and Evaluation (CE)
Concluding – My hypothesis was correct in that the time taken for one complete swing is directly proportional
to the length of the string. However, my results show that it is directly proportional to the square root of the
length of the string. All the points for the graph on the right lie on a straight line so the conclusion is very
reliable over this range. It seems likely that the same trend would continue if the string was made longer or
shorter.
NO REFERENCE GIVEN
Evaluating – The results seem to be very reliable over the range of lengths investigated. This is shown by the
fact that all points on the graph on the right fit exactly on a straight line. There are no anomalous results or
anomalies to be seen in the trend of the graph.
Sources of weaknesses and error in the procedure include:
1.
2.
I had to estimate where the centre of the bob was when measuring the length of the string. I estimated the
uncertainty in this as 1 mm. Also, when measuring the length beyond 1 metre, it must be done in two parts
using metre rulers.
Human reaction time: This come in two parts:
a) When using the stop watch: This source of error roughly cancels out as the human reaction time to
start and stop the watch as the same event is being observed, and reacted to in the same way, each
time. Errors are produced by any variability in the reaction time of the individual which could be
affected by many things. Taking more time measurements may give a slightly more accurate average
for each length, but not by much.
b) When deciding when one full swing has taken place: This was done by my judgement. However,
several improvements could be made for improving the accuracy of this measurement and they are
outlines in the improvements section below.
Very short lengths will run into logistical issues. It could be hard to measure the number of complete swings if
they happen very quickly. For very short lengths the trend may not continue. It is not possible to try lengths
shorter than the diameter of the bob, for instance.
Improvements – The procedure used was simple and straightforward and no difficulties were encountered.
Several improvements would add to the accuracy of the result:
1.
2.
3.
4.
A longer ruler could be placed level with the point of suspension, and a set square could be placed along
the flat side and just touching the bottom of the pendulum. This distance could then be measured more
accurately than trying to guess where the middle of the bob is.
The diameter of the bob could be accurately measured with some vernier callipers so that the true length
of the pendulum could then be calculated.
The thread used was quite stretchy. If the investigation was repeated I would replace it with something
more rigid, such as extra strong button thread.
A greater range of lengths both longer and shorter than what I measured should be conducted. At very
long lengths, a stronger string and a bob with more mass maybe needed to counter air resistance. Shorter
lengths would reach a limit would be reached where the pendulum moves too quickly to be accurately
counted. The use of an electronic Pasco sensor such as a light gate could help measure very fast periods
accurately. Also, a very high speed digital video camera that could accurately record the position of the
bob and the elapsed time.
5.
More repeats could be taken but I don't think this would add much to the accuracy of the conclusions.
6.
The investigation could be extended by investigating the relationship between period and length of string
for circular swings.
- 20 -
- 21 -
- 22 -
- 23 -
- 24 -
- 25 -
- 26 -
- 27 -
- 28 -
- 29 -
- 30 -
- 31 -
- 32 -
- 33 -
- 34 -
- 35 -
- 36 -
You must know these
chemical tests off by
heart!
- 37 -
- 38 -
Studying Effectively
You need to organize yourself to study effectively. To manage time effectively you should set yourself a
schedule of study in order to organize and prioritize your studies in the context of competing activities of sport,
family, etc. Follow up on the priorities you have set for yourself, and don't let others or other interests, distract
you from your goals. One way to help with this is to create a study schedule. An example of a study schedule is
this:
Preparing for Tests and Exams
Create study checklists
Identify all of the material that you will be tested on-- list notes, formulas, ideas, and text assignments you are
accountable for. This checklist will enable you to break your studying into organized, manageable chunks,
which should allow for a comprehensive review plan with minimal anxiety
Create summary notes and "maps"
Briefly map out the important ideas of the course and the relationships of these ideas. Summary notes should
display lists and hierarchies of ideas. Creativity and a visual framework will help you recall these ideas.
Create flashcards
Flashcards are useful for definitions, formulas, or lists that you need to have memorized--put topics on one side
of the card, answers on the other. Flashcards will enable you to test your ability to not only recognize important
information, but also your ability to retrieve information from scratch
- 39 -
Glossary
WORD
MEANING
abdomen
part of the body between the chest and hip, containing organs like the
stomach, liver and intestines.
absorb
soaking something up from the surroundings. A sponge absorbs water.
acid
a substance that turns litmus red . Has a pH of less than 7.
acid rain
rain containing sulphuric acid and nitric acid. Acid rain has a pH of less than
5.6.
adapted
when a cell or organism has certain features to help it to do a particular job.
When the shape of a cell helps it to do its job it is said to be 'adapted' to its job
or function.
addictive
a drug that causes the user to become dependent on it.
aerobic
the main respiration reaction in cells. It uses oxygen from the air and glucose
from respiration food to release energy . The waste products are carbon
dioxide and water.
alcohol
one of a group of chemicals with similar properties. Ethanol is the scientific
name for the chemical found in alcoholic drinks.
alcoholic
someone who is dependant on alcoholic drinks.
alkali
a substance that turns litmus blue. an alkali has a pH of more than 7. Another
name for a base that dissolves in water.
alkaline
with a pH of more than 7.
alternating current
an electrical current that flows one way then another. Generators and the
mains supply alternating current.
alveoli
tiny pockets in the lungs at the ends of the bronchioles, where oxygen diffuses
into the blood and carbon dioxide diffuses out.
amino acid
the molecules that proteins are made of.
ammeter
a piece of equipment used to measure electrical current.
amp(A)
the unit for measuring electrical current.
anaerobe
a living thing which survives without oxygen.
anaerobic respiration
respiration without oxygen, which takes place when cells cannot get enough
oxygen to meet their energy needs by aerobic respiration.
anode
positive electrode in electrolysis.
antibodies
proteins that destroy particular microbes. They are made by white blood cells.
antitoxins
chemicals that destroy toxins. They are made by white blood cells.
anus
the opening at the end of the gut.
aqueous solution
a solution of something in water.
- 40 -
armature
the turning part of a motor or generator.
artery
a blood vessel that carries blood away from the heart.
atom
the smallest particle of an element. it has no overall electric charge.
atomic mass
the relative mass of an atom. Roughly how many times heavier it is than an
atom of hydrogen.
atomic number
the number of protons in an element's atom.
atrium
the upper space on each side of the heart. it receives blood from the veins.
attract
pulling something closer.
auxin
plant growth hormone. it is found in the tips and shoots and the roots.
bacterium
a single celled microbe without a cell nucleus can cause a disease.
barrage
large dam across a river to control the flow of the tides.
base
a substance with reacts with an acid to form a salt. some bases are alkalis.
battery
two or more electrical cells used together.
bauxite
a rock containing aluminium.
biodegradable
something which will decay naturally
bronchi
pair of large air tubes from the trachea to the lungs.
bronchioles
small air tubes that branch out from the bronchi inside the lungs.
capillaries
tiny blood vessels that link arteries and veins.
carbon monoxide
very poisonous colourless gas. it stops red blood cells carrying enough
oxygen around the body.
catalyst
speeding up a chemical reaction.
cellulose
the substance that plant cell walls are made from.
cholesterol
a fatty substance found in some foods. it can clog up arteries and lead to heart
disease.
chromosome
a thread like strand found in the nucleus of a cell. made from DNA and contain
instructions for a living thing.
cilia
small hairs on the surface of some cells.
circuit breaker an
electromagnetic switch the breaks the circuit if the current gets too big.
convection current
a flow of liquid or gas caused by part of it being heated or cooled more than
the rest.
digestive system
organ system used to break down food and change it into a form the body can
use.
diabetes
when the pancreas produces too little insulin.
discharge
removing electrical charge from something.
- 41 -
discontinuous deposition
when the sedimentary rocks found at a place were not laid down continuously,
but at different times.
electrolyte
a liquid that conducts electricity
emulsion
a mixture of tiny droplets of one liquid blended throughout another liquid.
epithelium tissue
layer of cells that cover different body surfaces,
ethene
a hydrocarbon gas.
faeces
the undigested and unabsorbed remains of food.
fractional distillation
a process for separating a mixture
fruit
an organ that carries the seeds of flowering plants. can be fleshly or dry.
fuse rating
the maximum current that a fuse will conduct without melting.
gastric juice
digestive juice made by glands in the stomach lining. it is very acidic and
contains enzymes to break down proteins.
global warming
gradual heating of the earth's atmosphere. it is caused by the 'greenhouse
effect'.
gravitational potential energy
the kind of energy stored by anything that can fall to the ground.
gullet
the tube from the back of the mouth to the stomach. muscles in it contract and
relax to push the food along.
heat conductor
a material that lets heat energy flow through it easily.
hydroxide
a compound containing
immune
protected against catching a disease because the body has already made the
right antibodies.
insoluble
something that will not dissolve
kidneys
a pair of organs used to clean the bolld. they remove the urea in the blood and
make it into urine.
kinetic energy
the kind of energy in moving things
lactic acid
the waste product of anaerobic respiration. if it builds up in the muscles it
makes them ache.
litmus
a simple kind of indicator. it is red in acids and blue in alkalis.
metal oxide
a compound of a metal and oxygen.
metamorphic
a rock that has been changed by great heat or pressure(e.g. marbel)
native
when somehting occurs in nature as the element itself, not as a compound
newton
the unit for force.
ohm (W)
the unit for measuring electrical resistance
oil
a fossil fuel made from the remains of animals
optic nerve
the nerve that carries messages from the retina to the brain
- 42 -
ore
a rock that contains useful minerals
organ
a group of different tissues working together
organ system
a collection of organs working together
organism
any living thing. An organism must do all seven of the 'life processes'.
osmosis
when water flows through a semi-permeable membrane so that the
concentration on either side becomes more equal
overload
a fuse is overloaded if the current gets too big and melts it
oxide
a compound of an element and oxygen
oxidise, oxidation
adding oxygen to a chemical, removing electrons, removing hydrogen
oxygen
a colourless gas that makes up about 20% of the air. It is produced by
photosynthesis and used up in respiration
oxygen debt
the amount of oxygen needed to remove the lactic acid left from anerobic
respiration
palisade cell
a cell found in leaves, which contains many chloroplasts
palisade tissue
many palisade cells grouped together
pancreas
the organ that secretes digestive juices and hormones
parallel (electricity)
when the current in an electric circuit can flow along different routes
period
horizontal row of elements in the Periodic Table
Periodic Table
chart with the chemical elements arranged in order of atomic number.
Elements with
similar properties
appear in the same coloumn
permanent magnet
something that attracts iron all the time
pholem tissue
living cells grouped together to carry dissolved food substances from the
leaves to other parts of the plant
photosynthesis
process that plants use to make their own food. It neds light to work. Carbon
dioxide and water are used up. A sugar called glucose , and oxygen are
produced
photosynthesise
making food by photosynthesis
plant hormone
chemicals that controls the way a plant grows
plant organ
group of different plant tissues working together to do an important job
plasma
the liquid part of the blood, which is mainly water. It carries many substances
around the body (eg hormones, waste carbon dioxide and urea, nutrients
platelets
tiny pieces of cell in the blood that release chemicals to help blood clot. They
come from cells in bone marrow
plutonium
a fuel used in nuclear power stations
pole
the ends of a magnet, where its effects are strongest
polyethene
the chemical name for polythene. Its a polymer of ethane
- 43 -
polymer
a long molecule made from thousands of smaller ones (monomers). Plastics
are polymers
potential difference
another name for voltage
potential energy
the scientific name for 'stored' energy
power
how quickly something transfers energy
power line
overhead or underground cables that carry electricity
process
sorting out information
product
a substance formed by a chemical reaction
property
a way that a substance behaves
proportional
two quantities are proportional to each other if doubling one of them makes
the other one double too
protein coat
outer coating of a virus
proteins
important substances used up for growth and repair
proton
tiny positevely charged particle in an atoms nucleus
pupil
gap in the middle of the isis of the eye
pure
a single substance, not mixed with anything else
pus
the remains after many microbes have been ingested by white blood cells at a
spot or cut
pylon
a tall tower holding up overhead power cables
quarry
a place where useful rocks are dug out of the ground
quicklime
substance made by heating limestone. Its chemical name is calcium oxide
radiate
giving off waves of energy. A candle radiates light and heat energy
radiation
the way heat travels as waves of energy through space or transparent
materials. This can also refer to alpha, beta, gamma radiation
radioactive waste
dangerous waste from nuclear power stations
rate
the speed of a chemical reaction
raw materials
another term for a reactant
reactant
a substance used up in a chemical reaction
reactive
a substance that is likely t react
reactivity Series
list of metals and non metals arranged in order of how reactive they are
receptors
cells that detect change in the body or its surroundings
rectum
the last part of the large intestine, leading to the anus. It stores Faeces
red blood cells
the cells that give blood its colour. They contain haemoglobin, which carries
oxygen around the body
- 44 -
reduce/reduction
taking oxygen away from/adding hydrogen to a compound in a chemical
reaction. Also defined as: taking away electrons (oxidation) adding electrons
(reduction).
reducing agent
a chemical that will reduce other substances
refinery
place where the chamicals in crude oil are seperated and purified
reflect
bouncing something backfrom a surface
reflex action
an automatic response to a stimulus, often to protect the body from harm
relax
when a muscle relaxes after contracting it goes back to its original shape
relay
an electromagnetic switch for turning large currents on safely
renewable
an energy source that can be replaced or used again and again, and will never
run out (eg solar power)
repel
pushing something away
resistance
how difficult it is for an electrical current to flow through something
resistor
an electrical component that decreases the current in a circuit
respiration
chemical reaction inside cells to release energy from glucose
response
how the body reacts to a stimulus that has been detected (eg opening up the
pupil in dim light
retina
the back of the eye. It contains receptors that are sensitive to light
ripple mark
patterns left behind in sedimentary rock from the time when the sediment was
under water
rock cycle
all the processes which form rocks, linked together
root
plant organ used to hold the plant in the gound and take water and mineral
salts out of the soil
root hair cell
cell found in the roots. It has a large surface area to help the cell absorbs
water quickly
root hair tissue
many root hair cells grouped together
rusting
corrosion of iron by water and oxygen
sacrificial protection
allowing a piece of reactive metal to corrode so that an object made of a less
reactive metal does not
saliva
secretion from the salivary glands. It contains enzymes to break down starch,
and mucus to help food pass smoothly down the gullet
salt
a compound formed when an acid eacts with a base
scab
hard protective covering over a cut that forms when a blood clot dries
sclera
protective outer layer of the eye
secretion
useful substance (eg tears, saliva, hormones) made by gland cells
sediment
tiny particles that settle to the bottom of a liquid
- 45 -
sedimentary
rock formed by the compression and cementing of material that has settled at
the bottom of the sea
seed
grows into a new plant. Made by flowering plants and conifers
semi-permeable
a membrane that will let small particles, like water, through it but not large
ones
sensory neurone
a nerve cell that carries messages from a receptor to the brain or spinal cord
series
electrical components connected 'in line' so that all of an electrical current
flows through each one, one after another
sex organ
the stamea (male) and carpel (female) in a flower. They make the male and
female sex cells
slaked lime
a base made from limestone. its chemical name is calcium hydroxide
small intestine
the organ used to digest and absorb food
solar cell
a kind of batterythat generates electricity using energy from the Sun
soluble
something that can dissolve in a liquid (eg salt is soluble in water)
solution
a solute (substance) dissolved in a solvent (liquid, usually water)
solvent
a chemical used to dissolve something
solvent abuse
breathing in solvent fumes on purpose
sound energy
the kind of energy given out by something that makes a noise
South Pole/South-seeking pole
the end of a freely suspended bar magnet that points south
spinal cord
large bundle of nerve cells that carry messages to and from the brain. It runs
down the back, inside the spine
stain
dye used to colour parts of a cell to make them easier to see
stainless steel
mixture of iron with chroniun, corbon and other elements. It does not rust
starch
carbohydrate that plants use as a store of food
stem
leaves
plant organ used to support a plant and take water and mineral salts to the
stimulus (plural stimuli)
change within the body or in its surroundings that receptor detects (senses)
stomach
organ used to help break down food. It secretes digestive juices
stomata (singular stoma)
small holes on the underside of leaves which let gases into and out of the
leaves
part of a plant where a food substance can be stored
storage organ
sucrose
the chemical name for the sugar used in cooking. Some plants (eg sugar beet)
make it from glucose
sugars
group of carbohydrates that dissolve in water and taste sweet
sulphur dioxide
a gas that is produced in small quantities when fossil fuels are burnt. It is a
cause of acid rain
surface area
the total area of all surfaces of a shape
- 46 -
suspensory ligaments
part of the eye. They work with the ciliary muscle to hodls the lens in place
and changes its shape
symbol equation
shorthand way of showing what happens in a chemical reaction using symbols
symptom
sign that the body has a disease
target cell
a cell that is affected by a hormone
target organ
an organ that is affected by a hormone
taste bud
receptor on the tounge which is sensative to flavours
tactonic plate
a section of the Earths lithosphere
tempory magnet
something that can be made to attract iron when needed
terminal
where an electrical connection in made
thermal
decomposition breaking down a compound by heating it
thermal
energy another name for heat energy
thorax
the chest, containg the lungs and heart
tides
twice-daily rising and falling of sea level, caused by the pull of the Moon
tissue
a group of the same cells all doing the same job
tabacco the
dried leaves of the tabacco plant
toxin
poisonous substance made by a living thing
trachea
the main air tube to the lungs
transfer
the word used for heat or energy moving from place to place
transformer
piece of equipment that increases or decreases voltage. A step-up transformer
increses voltage and a step-down transformer decreases voltage
transmit
getting electricity from one place to another
transpiration
loss of water from plants leaves
transpiration stream
the flow of water up through a plants roots and stem to its leaves
transport (in earth science)
when eroded fragments are moved away from their 'parent rock' by wind or
water
turbine
a machine that is turned by a moving fluid
unit
a unit for measuring the amount of electrical energy transfered. 1 unit is the
same as 1 kilowatt-hour
universal indicator
a special mixture of indicators. It gives a different colour depending on how
weak or strong an acid or an alkali is
unlike
opposite charges os magnet poles
uranium
a fuel used in nuclear power stations
urea
waste product from the breakdown of unwanted amino acids by the liver
urinate
getting rid of urine when you go to the toilet
- 47 -
urine
solution of the bodys waste products, which are removed from the blood by
the kidneys
vaccination
being given an injection of a vaccine to help the body protect itself against
disease
vaccine
weak or dead disease causing microbes put into the body on purpose. White
blood cells make the right antibodies and the person becomes immune
valve
part of a vein or the heart that stops the blood in it from flowing the wrong way
vapour
another name for gas
vegetable
any plant food that is not a fruit
xylem tissue
xylem cells grouped together in tubes that carry water and mineral salts up
from the plants roots to the leaves
- 48 -
- 49 -
- 50 -
Download