1.1 Science is Part of
Everyday Life
1. Science is the knowledge of things that
happen in nature and the systematic study of nature and how it affects the
environment and us.
2. Things that happen in nature are also
known as natural phenomena.
3. Science helps us to understand natural
phenomena, to understand ourselves, to make discoveries and to gain knowledge.
4. Science improves our standard of living
and the quality of our environment.
5. Physics, chemistry and biology are the
three main branches of science.
6. The study of science requires a positive
attitude.
7. Example of natural phenomenon is:
lighting strikes, growth of human from babyhood to adulthood, flowers
blossoming, water evaporation, ball falling to the ground, ice melting, the
growth of animals and plants, foundation of rainbow and many more.
The
importance of science in everyday life
- Science is very important in our daily
life. We use the knowledge of science to make machines and develop new
technologies.
- These machines help us to do our work
more efficiently. The machines also make our life more comfortable.
- Technology is the application of science
knowledge for our needs and helps us to improve our standard of living.
- Contributions of science and technology
to the lives of human beings: Health, Comforts of life, Commerce,
Transportation, Security, Medicine, Communication, Space exploration,
Agriculture and Entertainment.
Careers
related to science
- Science has three main branches of
studies, namely chemistry, biology and physics.
- Each branch of science has careers
closely related to it. Therefore, you must be very good at science if you are
interested in careers related to science.
Science also has various fields of scientific
study, such as:
-Political science > national science
and a branch of social science that is associated with government, organizations
and nations in a practical way
-Applied science > used in various type
of work
-Sport science > combines various fields
of knowledge to used in sport
-Computer science > the study of the
basic principles and uses of computers
- Example of careers related to science:
science teacher, doctor, biochemists, computer programmers, engineers,
astronomers, pharmacists, dentists, sport physiologist, sport psychologist and
others.
- The following information on various
careers and their subject requirements can help you to plan your career.
Careers
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Major subject requirements
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Astronomer
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Physics
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Dentist
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Biology
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Engineer
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Physics and Chemistry
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Pharmacist
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Biology and Chemistry
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Science teacher
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Physics, Biology and Chemistry
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1.2 Your Science Laboratory
Scientists usually work in a laboratory. We
will also work in a laboratory when we carry out scientific investigations
during our science lessons.
Laboratory
safety rules
The laboratory is a place equipped with
apparatus for conducting experiments, investigation and tests. So, we need to
work safely in the laboratory. Accidents
can happen if we are careless. Here are some laboratory safety rules that we
must follow while working in a laboratory.
- Enter the laboratory with your teacher’s permission.
- If the class arrives before the teacher, line up outside the
laboratory and wait quietly.
- After entering the laboratory, go to your places without
jostling or grabbing of stools.
- No food or drinks should be taken into the laboratory.
- Open all doors and windows while in the laboratory.
- Pupils must not perform experiments without permission.
- Read and understand the instructions given before you attempt
to do the experiment. When in doubt always ask your teacher for help and advice.
- Always keep laboratory clean.
- Label all containers clearly and the label should draw
attention to any particular hazard.
- Always read the label on the bottle before using the chemicals
in contains.
- Do not play, run or walk around unnecessarily in the
laboratory.
- Handle all apparatus correctly and carefully.
- Breakages and faulty equipments must be reported to the teacher
at once.
- Do not waste any chemicals. Use only the required amount.
- Do not pour unused chemicals back into their containers.
- Water, gas and electricity must not be waste.
- Do not damage any fitting or the electrical mains in the
laboratory.
- Do not obstruct passage or access to emergency exits or fire
extinguishers.
- Do not light a Bunsen burner with a piece of paper. Turn off
the gas after used.
- Do not handle chemicals with your fingers. Always use a
spatula.
- Do not taste any chemical or inhale any gas unless asked to do
so by the teacher.
- When heating any solution in a boiling tube, always make sure
that the mouth of the tube is not pointed to anybody.
- Solid wastes must be put in the bins provided. Do not throw
solid waste into the sinks.
- Any mishaps, cuts, burns scalds or substances which get into
your mouth must be reported to the teacher at once.
- After the experiments, wash all used apparatus and return them
to their respective places.
- Do not remove any apparatus or chemical from the laboratory.
- Wash your hands thoroughly.
- The benches must be left clean and tidy.
- All taps and switches must de turned off.
Hazardous
substances found in the laboratory
There are many substances in the science
laboratory. Some of these substances are hazardous. We use hazard warning
symbols to show the danger of the substance. Below are some common hazard
warning symbols.
Laboratory Apparatus
We use apparatus
when doing scientific investigations. You will learn how to use the laboratory
apparatus by doing scientific investigations in the laboratory. You should also
learn how to draw the apparatus you use in a scientific investigation. Here are
some common apparatus that you can find in the laboratory.
1.3 Steps in a Scientific
Investigation
Scientists obtain
the knowledge of science by doing scientific investigation. The scientific
method of investigation is a method carried out based on scientific rules and
principles that are accurate, disciplined and systematic.
- Identify the problem: Determining the problem to be examined.
- Forming a hypothesis: Making a smart guess to explain the
problem.
- Planning an investigation: How to rest the hypothesis, what
apparatus to use, how to put the apparatus together, what materials are
needed and what procedure to follow.
- Controlling the variables: Changing one or more of the
conditions of the experiment.(a)Constant variable (b)Manipulated variable (c)Responding variable
- Carrying out experiment:
(a) Collecting data: Recording of data
(b) Analysing data: Analysis of data in the form of a table or
graph
(c) Evaluating data: Interpretation of data to show the relationship
between the length of a string and the
swinging time of a pendulum
(d) Making conclusion: Making a statement regarding the outcome of
experiment based on the hypothesis.
6. If the hypothesis is right, science theory is build. If the
hypothesis is wrong, back to the step 2 (Forming a hypothesis).
7. Writing a report: Writing a report of the finding of the experiment.
1.4 Physical Quantities and
Their Units
- Physical
quantities are quantities that can be measured.
- The five base
quantities are length, time, mass, temperature and electric current. Pre fixes
are used when the quantities that we measured have very small values or very
big values.
- Physical
quantities are measured in SI units. The symbol S.I.
is an abbreviation for the French term Le Système International d’ Unités. It means
International System of Units.
Physical quantity SI unit Unit symbol
Length Meter m
Mass Kilogram kg
Time
Second s
Temperature Kelvin K
Electric current Ampere A
Prefix Symbol Value Standard
Form
Giga G 1000000000 109
Mega M 1000000 106
Kilo k 1000 103
Hecto h 100 102
Deca da 10 101
Desi d 0.1 10-1
Centi c 0.01 10-2
Milli m 0.001 10-3
Micro μ 0.000001 10-6
Nano n 0.000000001 10-9
Pico p 0.00000000000001 10-12
1.5
Is Mass the Same as Weight?
1.1 Learning how to Use Measuring
Tools
Measuring
length
- Length is the distance between two points.
- The S.I. unit for length is kilometre (km),
metre (m), centimeter (cm), and millimeter (mm)
- Different tools are used to measure
different type of lengths.
The relationship between the units:
1cm=10mm
1m=100cm
1km=1000m
Measurement of the length
-The length of a straight line can de
measured with metre ruler, half-metre ruler, ruler or measuring tape.
- thread and a ruler are used to measure
the length of a curved line.
- An opisometer can be used to measure the length
of a curved line.
- When we are taking reading from the scale
ruler, the correct eye position is very important in order to obtain an
accurate reading.
- A number of readings should be taken to
get an average value that is more accurate.
The accuracy of a measurement can be
improved if the person doing the measurement can
avoid making errors. The
error caused by an incorrect eye position when taking measurement
is known
as parallax error.
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Measurement of the diameter
-Internal diameter of a container
The internal diameter of a container like a
beaker
or boiling tube can be measured using a
pair of
internal calipers and a ruler.
The distance between
the two arms of the calipers marks the
inside
diameter of a container.
-External
diameter of a container
The external diameter of a container like a
beaker
or boiling tube can be measured using a
pair of
external calipers
and a ruler.
Measure the
distance
between two
points of the calipers with a ruler.
-Diameter of a spherical
object
The diameter of a
spherical object can be measured
with two wooden
block and a ruler or two set
squares and a
ruler.
-Vernier calipers
Vernier calipers
are used to measure small distances
accurately. The
internal jaws are used to measure the
internal diameter
of a container. The external jaws are
used to measure
the external diameter of a container.
This instrument
gives readings with an accurately of
up to 0.01cm (2
decimal places). The Vernier calipers
have two scales.
The main scale is graduated in centimeter
units. The Vernier
scale, a scale of 9mm, has 10 divisions.
One division is
0.9mm.
Measurement of
the Area
Area is the total
surface occupied by an object. Area is measured in units of square metres (m2),
square centrimetres (cm2) and square millimeters (mm2).
Different tools are used to measured different types of lengths.
Measurement of a
regular shape
Regular shape
area can be calculated by using Mathematical formulae:
Measurement of an
irregular shape
-The area of irregular shape like leaves and
petals
can be estimated by using a graph paper.
- A graph paper has small squares boxes.
-The irregular shape object is estimate by
counting the number of square
covered by the tracing.
- A check mark is made on the graph paper
for each
full
square and half full squares,or more than half full squares.
-Then, the number of check marks are counted.
-The area of the object is estimate by multiplying
the number of check marks
with
the area of one square on the graph paper.
- More accurate approximate of area can be
obtained by using a graph paper with squares that are smaller in size.
Measurement of Volume of Liquids
- Volume is the total area occupied by an
object.
- Volume is measured in litres (l), milliliters
(ml), cubic metres (m3) and cubic centrimetres (cm3).
Measuring cylinder-The measuring cylinder
is a vessel that ha its outside surface marked (graduated) with units of volume
in cubic centrimetres. To obtain an accurate reading of the volume of a liquid,
the reading has to be taken above or below the curve of the meniscus.
Pipette-The pipette is a glass tube with a
bulb at its centre and a spout at one end. The other and has a mark indicating
the fixed volume of liquid that the pipette can measure. Pipettes in the
laboratories are usually used to measure volumes of5, 15, 20 and 25ml
accurately.
Burette-The burette is used to deliver
volumes of liquids more accurately than a measuring cylinder.
Measurement of Volume of Solids
The volume of regular and irregular shape
solids can be determined by using the water displacement method.
1.1 The Importance of Standard
Units in Everyday Life
- The standard units used are the S.I.
units.
- The use of standard units makes it easier
for people from different countries to communicate with each other.
- People need to communicate when they are
involved in interactions such as buying and selling, international business,
industries, and transportation.
- Furthermore, the use of a standard unit
means a measurement in that unit has the same value anywhere in the world. For
example, if you were to buy 1kg of sugar in Malaysia
and 1kg of sugar in Thailand,
you would get the same amount of sugar from each country. - If standard units
absence, accurate and precise measurement would be a problem, people from
different countries will face difficulties to communicate with each other
especially in interactions such as business and transportation and scientists
around the world would have difficulty in comparing studies that have been
carried out.
Length-British Imperial System-inches,
feet, yard, chain, mile -metric system-metre, kilometre
Area-British Imperial System-inches2,
feet2, yard2, mile2, acre-metric system-metre2,
kilometre2
Volume- British Imperial System-inches3,
feet3, yard3, gallon-metric system-metre3
Mass or weight- British Imperial
System-pound, ounce, kati, tahil, ton, pikul
-metric system-gram, kilogram
Length-12inches=1foot, 3feet=1yard, 22yard=1chain, 10chain=1furlong,
8furlong=1mile, 5280feet=1mile, 1760yards=1mile, 1inch=25.4mm, 1foot=0.305,
1mile=1.6km, 1foot=0.093m, 1m=3.3feet, 1km=0.6mile
Area-144 square inches=1 square foot, 9 square foot=1 square yard, 4840
square yard=1 acre, 640 acre=1 square mile, 1 acre=4046.9m2, 1m2=10.8feet2
Volume-1728 cubic inches=1 cubic foot, 27 cubic feet=1 cubic yard, 1 foot3=0.028m3,
1 gallon=4.5 litre, 1ml=0.0000g inches3, 1m3=35.3 feet3,
1 litre=0.22 gallon
Mass-437.5 grains=1 ounce, 16 ounces=1 pound, 14 pounds=1 stone, 12
ounces=1 pound, 1 pound=0.45kg, 1ton=1016kg, 1kati=0.6kg, lg=0.035ounce,
1g=0.026tahil, 1kg=1.65katis
