5. •We want to know why and how all these things
happen. We search for an answers. Thus, the study of
science gives us answers.
•Science is the systematic study of nature and how it
affects us and the environment.
•The information produced from the study of science is
known as scientific knowledge.
•Scientific knowledge develops as new scientific
discoveries are discovered every day.
6. •Using scientific knowledge, we invent many useful
devices such as light bulbs, telephones and
computers. The application of scientific knowledge
for the use of mankind is called technology.
•We use technology almost every aspect of life
thus making science part of our every day life.
7. Importance of Science
•Science plays important roles in our daily life.
a.Science helps us to understand ourselves.
Knowing how our body works, helps us to take
better care of our health.
b.Science also helps us to understand our
environment. This helps us to improve the
quality of our environment and conserve it for
our future generation.
c.Science makes our life more comfortable. We
invent various machines to help us to work faster
and more efficiently.
8. Use and benefits of science in daily life
•Facilities such as electricity and tap water make life easier and
more comfortable.
•Various appliances such as washing machine, microwave oven
and vacuum help us to do our housework faster.
In Homes
9. Communication
•Communication is easier and faster with the use of television,
telephone, mobile phone, facsimile and computer.
•Global communication is now possible with the use of
communication satellites, e-mail and the internet.
10. Transportation
•Transportation is easier, faster and more comfortable.
•Modern public transports such as commuter trains and light
rail transit reduce congestion in cities.
•The design of better roads and highways increases the safety of
users.
11. Construction
•Buildings and structures are now built with strong materials
such as steel, concrete and reinforced glass.
•Powerful machinery such as cranes, tractors and bulldozers are
usually used in construction works.
12. Agriculture
•Machines are used to carry out heavy and difficult tasks
such as ploughing and harvesting.
•Plant breeding, new agricultural techniques, fertilizers and
insecticides contribute greatly in increasing the world’s
agricultural products.
13. Medicine
•More diseases can now be cured with the discoveries of new
drugs, vaccines, antibiotics and the invention of better surgery
techniques and equipment.
•Diseases can be diagnosed and detected earlier with various
tests and devices such as X-ray machine and ultrasound
scanning device.
14. Careers in science
•Science offers various career opportunities
according to one’s area of interest.
a.Doctor – a person has been trained in and
practises medicinal science.
b. Veterinarian – an animal doctor.
c. Pharmacist – a person who dispenses
medical drugs and advise their uses.
15. d. Engineer – a skilled person who designs, builds
or maintains engines, buildings, bridges or
roads.
e. Architect – a person who design buildings and
advises on their construction.
f. Chemist – a person trained in chemistry.
16. •Science is divided into a number of areas of study:
a. Biology – the study of life.
b. Physics – the study of matter, energy, force and
motion.
c. Chemistry – the study of composition and
chemical properties of substance.
d. Astronomy – the study of planets and stars in
the Earth.
e. Geology – the study of rocks, minerals and the
structure of the universe.
f. Meteorology – the study of weather and climate.
g. Biochemistry – the study of chemical process in
living organisms.
17.
18. Science Laboratory
•The place where a scientist works is called laboratory.
•Students carry out scientific investigations or
experiments during science lessons in science
laboratories.
•There are rules and safety precautions that must be
followed by the students in order to avoid accidents.
19. Rules and Safety Precautions
Never enter the laboratory unless a teacher is
present.
Do not eat, drink or taste chemicals.
Always follow the teacher’s instructions.
Never touch chemicals with your bare hands. Use a
spatula.
Read a label on a reagent bottle before using its
content.
Turn off the Bunsen burner after use.
Do not pour back any unused chemical into its bottle
20. Do not throw solid wastes into the sink.
Wash and keep all apparatus after use.
Do not run or play in the laboratory.
Do not test anything without the teacher’s
permission.
Report any breakages to the teacher.
Keep the bench clean and tidy.
21. •We need to use apparatus to carry out experiments
Test tube
To hold a small amounts
of liquid or chemical.
Boiling tube
For heating small amounts
of liquid.
29. a. A Bunsen burner is used in the laboratory to heat
substance.
b. The Bunsen burner has an air – hole. The air –
hole can be opened or closed by turning the
collar.
c. When the air – hole is opened, the Bunsen
burner gives a blue flame. This is called a non –
luminous flame. The flame is very hot because
the gas is burned completely.
d. When the air – hole is closed. The burner gives a
yellow flame. This flame is easier to see and it is
called luminous flame. This flame is less hot and
produce a lot of black soot because the gas is not
burned completely.
31. e. The correct way to light up a Bunsen burner is
as follows:
•Close the air – hole by turning the collar.
•Hold a lighted match or a lighter at the top of the
barrel.
•Turn on the gas slowly. A yellow or luminous
flame will be obtained.
•Open the air – hole to obtain a blue or non –
luminous flame.
32. f. To avoid accidents when using a Bunseen
burner, the following precautions should be
taken.
•Use a lighter or a match to light up a Bunsen
burner instead of a burning paper.
•We must light up the match before turning on
the gas.
•When heating a test tube, hold the test tube at
an angle of 45 degrees. Use a test – tube holder
and do not point the mouth of the test tube to
yourself of your friends.
33. •Do not heat flammable substances like
alcohol directly.
•When not using the Bunsen burner
temporarily, close the air – hole to obtain
the yellow flame because this flame is
easily seen. Remember to turn off the gas
after using the burner.
35. •Some substances in the laboratory are
hazardous or dangerous.
•Hazard warning symbols are placed on labels
of bottles or containers of hazardous substances
to show the danger of the substances.
•As young scientists, you must be able to
recognize the symbols and know how to handle
the substances properly.
37. Flammable or
inflammable
•Easily catches
fire and burns
•Organic
solvents
such as
ethanol,
petrol or
kerosene
•Keep away
fromfire or
heat
sources.
Toxic /
poisonous
•Causes death
or harm to the
body if
absorbed
through the
skin, swallowed
or inhaled.
•Mercury,
chloroform,
lead,
benzene,
bromine,
sodium
cyanide,
hydrogen
sulphide
•Do not
inhale,
touch or
taste the
substances.
•Keep in a
locked
cupboard.
38. Corrosive
•Causes damage
to the skin or
eyes upon
contact
•Concentrated
acids and
alkalis,
bromine,
hydrogen
peroxide.
•Avoid
contact with
skin oreyes.
•Spill on body
parts should
be washed
away quickly
underrunning
water
Irritant / harmful
•Irritates causes
(itchiness and
rashes) skin,
eyes and
respiratory
system
•Ammonia
solution,
chloroform,
dilute acids
and alkalis
•Spill on body parts
should be washes
with a lot of water.
