Download - Apa itu sains?
1. Apa itu Sains?
Sains
•Pertumbuhan bayi
Contoh fenomena semulajadi
•Gerhana matahari•Peleburan ais• Pembentukkan pelangi
•Letupan gunung berapi.
Kajian yang sistematik tentang fenomena alam.
4 Geologi
6 Meteorologi
5 Astronomi
3 Kimia
1 Biologi
2 Fizik
Kajian tentang benda hidup
Kajian tentang tenaga dan kesannya ke atas jirim
Kajian tentang batuan, tanih dan mineral
Kajian tentang perubahan cuaca dan iklim
Kajian tentang jirim dan tindak balas antaranya.
Kajian tentang planet, bintang, dan objek lain dalam alam semesta
Bidang – bidang Sains
•Doktor•Pakar diet•Ahli botani•Ahli botani•Ahli farmasi•Ahli farmasi
•Ahli meteorologi•Ahli kimia•Jurutera•Arkitek•Saintis
•Angkasawan.
Kerjaya dalam sains
Kepentingan Sains
• Sains membantu kita memahami alam sekitar
• Sains meningkatkan taraf kehidupan
• Sains menawarkan kerjaya yang berasaskan sains
• Sains meyumbang kepada penemuan dan penciptaan baru.
2. A Science Laboratory
Hazard Symbols
Hazard Symbols
Symbol and meaning Examples
1
2
Highly flammable
Explosive
Petrol & Kerosene
Phosphorus
Alcohol / Ethanol
Sodium
Potassium
Hydrogen
Hazard SymbolsSymbol and meaning Examples
3
4Harmful / Irritant
Toxic / Poisonous
Chlorofom
Ammonia
Chlorine
Mercury Lead
Sodium cyanideHydrogen sulphide
Bromine
Hazard SymbolsSymbol and meaning Examples5
6
Corrosive
Radioactive
Sodium hydroxide
Hydrogen peroxide
Concentrated acids & alkalis
Uranium
Plutonium
Radium
Thorium
COMMON LABORATORY APPARATUS
CONTAINER
Conical flaskRound-bottomed flaskFlat-bottomed flaskBeaker
COMMON LABORATORY APPARATUS
Filter funnel
To filter mixturesof solids and liquids
To containgas
Gas jarCrucible
For heating chemicals
Test tube holder
To hold test tubes
COMMON LABORATORY APPARATUS
To hold hot objects
Crucible tongs
To conduct excess heat away
Wire gauze
To provide a flame for heating
Bunsen burner
To support apparatus during heating
Tripod stand
COMMON LABORATORY APPARATUS
Glass rod
For stirring liquids
For evaporating liquid from a solution
Evaporating dish
Syringe
To transfer small quantities of liquids
To hold the apparatus while experiments are being done
Retort stand and clamp
COMMON LABORATORY APPARATUS
To measure time
Stop watch
To measure temperature
Thermometer
To measure the volume of solutions accurately
Measuring cylinder
To measure a small volume of solutions
accurately
BurettePipette
To measure a fixed volume of solutions
accurately
Suction pump
An instrument to measure electric
current
An ammeter
BUNSEN BURNER
Barrel
Collar
Air-hole
BaseGas inlet
1. Air-hole open 1. Air-hole close
2. Luminous-gives
out light 2. Non-luminous does not give out light 3. Gives out a lot of soot
3. Does not give out soot [Gas is completely burn]
4. Suitable for heating- very hot
4. Not suitable for heating-not very hot
BUNSEN BURNER
Just remember one side only
BUNSEN BURNER
Steps in lighting a Bunsen burner
1
2
4
3
Close the air hole by turning the collar
Light a match and bring it near the barrel
Turn on the gas pipe
Adjust the collar on the Bunsen burner
3. The Steps in a Scientific Investigation
Steps in a Scientific Investigation
1 Identify the problem2 Making a smart guess/ hypothesis3 Plan the experiment4 Control the variables5 Carry out the experiment6 Recording/Collect data7 Analysing the data8 Interpreting the data9 Making conclusions10 Writing reports
4. Physical Quantities and Their Units
PHYSICAL QUANTITIES & THEIR UNITS
Quantity Unit Symbol of unit
Length metre m
Mass kilogram kg
Time second s
Temperature kelvin K
Electric current ampere A
Physical quantity Measured by using
1. Length
2. Mass
3. Time
4. Temperature
5. Electric current
A metre rule
Lever balance
Beam balance
Electronic balance
A stop watch
A thermometer
An ammeter
PREFIXES
Prefix Symbol Value of prefix
kilo- k 1000
centi- c1
100
milli- m1
1000
Examples show how prefixes are used
5. Weight and Mass
1. The amount of matter in the object
1. The pull of the Earth on the object
2. Always the same anywhere
2. Not always the same- depends on the force of gravity 3. Measured by using a spring balance or a compression balance
3. Measured by using a lever balance or a triple- beam balance
4. Measured in kilograms 4. Measured in newtons
WEIGHT IS NOT THE SAME AS MASS
Balance for measuring Weight
Spring balance Compression balance
Balance for measuring Mass
Beam balanceLever balance
Electronic balance
WEIGHT AND MASS
MassWeight
1 kg
60 kg
Earth Moon Outer space
10 N 0 N
1 kg = 1 x ( gravity = 10 ) = 10 N
10/6 N
600 N 100 N 0 N60 kg 60 kg 60 kg
Triple beam balance Lever balance
Beam balance Lever balance
Balance for measuring Mass
6. Measuring Tools
Measurement of Length
4. An opisometer (map measurer)
● to measure the length of a crooked line
● to measure the length of a curved line
● to measure the length of long straight line
● to measure the length of short straight line
Measurement of Length
5. External callipers
6. Internal callipers
Measurement of Length
Measuring the thickness of a beaker
External diameter = 2.2 cm
Internal diameter = 2.1 cm
Thickness of the beaker = External diameter – Internal diameter 2
= 0.1 = 0.05 cm 2
4.8 cm – 4.6 cm
= 0.1 cm = 1mm
2
Measurement of Length
The correct way to read the scale on a ruler
Measuring a curved line using a thread and a ruler
Measurement of Area
1
PMR 2008
Measuring the volume of liquids
To measure the volume of liquids
To measure a small volume of liquids accurately
To measure a fixed volume of liquids accurately
Use a suction pump to suck liquid into a pipette. Do not use your mouth
Measuring the volume of liquids The correct way to read the scale on a
measuring cylinder
Measuring the volume of liquids The correct way to read the scale on a measuring cylinder
Measuring the volume of liquidsTo improve the accuracy of the reading
. use a hand lens to read the scale
. put a piece of white paper behind the scale
WATER DISPLACEMENT METHOD To measure the volume of regular and irregular solids
Estimating the volume of irregular solids
WATER DISPLACEMENT METHOD
Estimating the volume of a cork
Volume of the cork = ( 58 – 52 ) ml = 6 ml = 6 cm³
WATER DISPLACEMENT METHOD
Estimating the volume of irregular solids
WATER DISPLACEMENT METHOD
WATER DISPLACEMENT METHOD
EUREKA CAN