What is Science?
•We see various natural phenomena in our daily life.
Natural Phenomena are things that happen in nature.
Lightning
Rainbow
Melting of Ice
The Fall of the Ball
Growth of a Baby into Adult
•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.
•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.
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.
Use and benefits of science in daily life
In Homes
•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.
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.
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.
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.
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.
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.
Careers in science
• Science offers various career opportunities
according to one’s area of interest.
a. Doctor – a person has been trained in and
practices medicinal science.
b. Veterinarian – an animal doctor.
c. Pharmacist – a person who dispenses medical
drugs and advise their uses.
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.
•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.
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.
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.
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.
•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.
Beaker
Conical Flask
Flat – Bottomed Flask
To hold bigger amounts of liquids or chemicals.
Measuring cylinder
To measure volume of
liquids.
Pipette
To measure a fixed volume
of liquids.
Burette
To measure small volumes
of liquid accurately.
Retort stand
To hold or support
apparatus.
Filter funnel
Used together with a filter
paper to filter mixtures of
solids and liquids.
Bunsen burner
To provide a flame for
heating.
Tripod stand
To support apparatus
during heating.
Wire gauze
To support apparatus and
ensure even heating.
Evaporating dish
To hold liquids for
evaporating.
Crucible
To hold solids for
strong heating.
Test tube holder
To hold a test tube
during heating.
Spatula
To transfer small amounts
of liquids.
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.
The parts of Bunsen burner
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.
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.
•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.
The correct way to hold a test
tube during heating.
•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.
Symbols
Danger of
substances
Examples
Handling
techniques
Explosive
•Easily explodes
when mixed
with other
substance
•Sodium,
potassium
•Concentrated
acids and
alkalis
•Keep in
paraffin
•Avoid contact
with water
•Keep away
from other
substances
including water.
Flammable or
inflammable
•Easily catches
fire and burns
•Organic
solvents
such as
ethanol,
petrol or
kerosene
•Mercury,
chloroform,
•Causes death or lead, benzene,
harm to the body bromine, sodium
cyanide,
if absorbed
through the skin, hydrogen
sulphide
swallowed or
inhaled.
Toxic /
poisonous
•Keep away
from fire or
heat sources.
•Do not
inhale, touch
or taste the
substances.
•Keep in a
locked
cupboard.
•Concentrated
acids and
•Causes damage alkalis,
to the skin or
bromine,
eyes upon
hydrogen
peroxide.
contact
Corrosive
Irritant / harmful
•Irritates causes
(itchiness and
rashes) skin, eyes
and respiratory
system
•Ammonia
solution,
chloroform,
dilute acids and
alkalis
•Avoid contact
with skin or
eyes.
•Spill on body
parts should be
washed away
quickly under
running water
•Spill on body parts
should be washes
with a lot of water.
Radioactive
•Gives out
radiation that
can cause cancer
or destroy bodily
tissues.
•Uranium,
plutonium, radium.
•Keep in special lead
containers.
See you next time!!