WELCOMEWELCOME

CHAPTER 1:CHAPTER 1:Introduction to Science

WELCOMEWELCOME

CHAPTER 1:CHAPTER 1:Introduction to Science

1.1 What is Science?1.1 What is Science?

1) Science is the systematic study of natural Phenomena and how it effects us and the environment.

2) Science is studied through observation and scientific investigation.

3) Natural Phenomena that happen in the environment can be explained through science.

Examples: a) the melting of ice

b) the birth of a babyc) lightningd) Earthquake (gempa bumi)

Chapter 1: Introduction to ScienceChapter 1: Introduction to Science

4) Science has the following uses and benefits:

a) it helps us to understand things around us.b) it make our lives easier, healthier and comfortable.c) it helps us to improve the environment.d) it trains us to think logically and creatively.

5) Science covers a very wide area of study:

a) BIOLOGY- The study of living things.

b) PHYSICS- The study of interaction of motion and forces.

c) CHEMISTRY- The study of chemical properties, their reactions and uses.

d) GEOLOGY- The study of rocks and minerals.

e) ASTRONOMY- The study of the stars and planets.

f) METEOROLOGY - The study of weather and climates.

6) Careers in Science including:

Doctor, Veterinarian, Pharmacist, Engineer, Architect, Chemist, Computer Doctor, Veterinarian, Pharmacist, Engineer, Architect, Chemist, Computer programmer, pilot, scientist, astronomer, dentist forensic, Biologist, programmer, pilot, scientist, astronomer, dentist forensic, Biologist, chemist and etc…….chemist and etc…….

(Exercise 1.1 page 4) –exercise book(Exercise 1.1 page 4) –exercise book

Mark (/) for true statements or (x) for Mark (/) for true statements or (x) for false false

statement.statement.

1)1) A natural phenomenon is an occurrence A natural phenomenon is an occurrence that involves only non living thingsthat involves only non living things

2) Science is an arrangement of knowledge 2) Science is an arrangement of knowledge about the environmentabout the environment

3) Knowledge of science can only be 3) Knowledge of science can only be obtained through experimentsobtained through experiments

4) Computer programming is a career in 4) Computer programming is a career in sciencescience

1.2 Science Laboratory1.2 Science Laboratory

*Laboratory Safety Rules and Precautions

(See text book pg 5).

*Common laboratory apparatus (see text book pg 7, 8 and 9).

• Outline drawing for laboratory apparatus (Pg 10)

Retort stand and clamp Gas jar Test tube

Round-bottom flask Beaker Conical flask

Hazard symbols1) Hazard symbols are recognizable symbols designed to warn about hazardous materials or locations

Corrosive (mengakis)

Highly flammable (mudah terbakar)

Explosive (mudah

meletup)

Toxic/Poisonous(Toksik/beracun)

Harmful/Irritant

(Berbahaya/merengsa)

See also textbook page 11

Radioactive(Radioaktif)

Exercise 1.2 (page 12)

Lighting up the Bunsen burner.

• What are the steps that you should follow to light up a Bunsen burner?

1. Close the air-hole using the collar on the Bunsen burner

2. Hold a lighted match (or a starter) at the top of the Bunsen burner.

3. Turn on the gas slowly to get ………………………

4. Open the air-hole to get ………………………

Luminous flame (yellow flame)

Non - luminous flame ( blue flame)

Think about it…• Why is it necessary to close the

air-hole first? Why can’t you just light the burner with the air-hole open?

1.3 Steps in Scientific Investigation1.3 Steps in Scientific Investigation

Identify the

PProblem

Propose a HHypothesi

s

Plan the EExperime

nt

CControl ontrol thethe

variablevariable (experimen

t)

Collect DData

AAnalyse and

interpret the data

Making CConclusio

n

Write a RReport

PHECDACR

• Exercise 1.3 (page 16)

Activity 1.5 : Scientific Investigation (pg 14) - REPORT

Date : ___________

Problem : How does the length of a simple pendulum affects its period of oscillation?

Hypothesis : The shorter the length of pendulum, the shorter the time taken for 10 oscillation. Variables : a) Constant : Mass of the pendulum bob

b) Manipulated : Length of the thread c) Responding : Periods of oscillation

Apparatus : Pendulum bob, string, retort stand and clamp, metre ruler and stop watch

One complete swing meaning A swing to B and swing

back to A

Retort stand String

Pendulum bob

Steps:

1) A pendulum with a 10cm long thread is prepared.

2) The pendulum is pulled to one side, then it is released. 3) The time taken for 10 complete oscillation is recorded

in a table.

4) The experiment is repeated using a pendulum of different lengths as shown in the table.

Results:

ExperimentExperiment Length of simpleLength of simplependulum (cm)pendulum (cm)

Time taken for 10 complete Time taken for 10 complete oscillation (s)oscillation (s)

11 1010 8.8

22 2020 13.2

33 3030 16.0

44 4040 18.4

55 5050 20.0

Reading 1 Reading 2 Average

Length of the pendulum Length of the pendulum (cm)(cm)

Tim

e t

ake

n (

s)Tim

e t

ake

n (

s)

10 20 30 40 500

12

20

8

4

16

Plot a graph:

Analysis : From the data, we can say that the pendulum with a longer string takes longer time to oscillate.

Conclusion : The time taken for the simple pendulum to make one complete oscillation increase with the length of the pendulum.

The hypothesis is accepted.

Question :

Which of the following is not one of the steps in using the

scientific method?

A)A)Making a hypothesisMaking a hypothesisB)B)Collecting a dataCollecting a dataC)C)Identify a problemIdentify a problemD)D)Making a theoryMaking a theory

1.4 Physical Quantities and Their Units1.4 Physical Quantities and Their Units

1) A physical quantity is a quantity which can be measured.

Physical quantityPhysical quantitySI Unit/symbolSI Unit/symbolMeasuring instrumentMeasuring instrument

Length Metre (m) Metre rule

Mass Kilogram (kg) Beam balance

Time Second (s) Stop watch

Temperature Kelvin (K) Thermometer

Electric current Ampere (A) Ammeter

Table 1.1: The SI units and measuring instruments

2) 2) Physical quantitiesPhysical quantities are measured in SI units. are measured in SI units.

3) SI units is the abbreviation of the French term 3) SI units is the abbreviation of the French term ““Le systeme International d uniteLe systeme International d unite” ”

= International System= International System

4) SI units are used as 4) SI units are used as standard unitsstandard units all over the all over the worldworld

5) Prefixes are used in the SI unit to state a 5) Prefixes are used in the SI unit to state a very very smallsmall or a or a very bigvery big value. value.

Table 1.4 symbols and values for prefixes (Pg 17)

Prefix Symbol Numerical Value

Value

mega M 1 000 000

6

10

kilo k 1 000 3

10

centi C 0.01 -2

10

milli m 0.001 -3

10

micro µ 0.000001 -6

10

Example:

Value of physical quantity Prefix form

• 5 000 000 k = 5 Mk

• 3 300 g = 3.3 kg

• 0.081m = 8.1 mm

• 0.000 006 A = 6µm

0.02 m = 2 cm4 000 g = 4 kg0.007 A = …………….9 500 m = …………….0.008 m = …………….

2cm4kg7mA9.5 km8 mm

Try it!

WeightWeight

1)1)The pull of The pull of earth’s earth’s gravitygravity on that object. on that object.

2)2)The The weight weight of an object of an object changechange depends on the depends on the gravitational forcegravitational force that that acts on the object at the acts on the object at the place.place.

3)3)The SI unit – The SI unit – Newton (N)Newton (N)

4)4) Measuring weight- spring balance, compression balance (pg 18)

MassMass

1)1)The The quantity of matterquantity of matter in in the object.the object.

2)2)The The massmass of an object is of an object is constantconstant everywhere- everywhere- because the quantity of because the quantity of matter in an object is the matter in an object is the same wherever the object same wherever the object is.is.

3)3)The SI unit- The SI unit- Kilogram (kg)Kilogram (kg)

4)4) Measuring mass-Measuring mass- beam beam balance, Lever balance and balance, Lever balance and electronic balance, electronic balance, chemical balancechemical balance

Beam balance – measure mass

Measuring lengthMeasuring length

1)Length is the distance between 2 points2)The SI unit for length – metre (m)3)Short lengths are measured in cm or mm while

long distance measured in km

a) Measuring the length of straight line

1)A metre ruler can be used.2)The correct reading obtained only when the eyes vertically above the mark on ruler

3) Parallax error occurs if the position of the eye is wrong when taking the reading

4) Measuring tape can be used to measure The length of long straight lines

b) Measuring the length of curved line

1)A piece of thread and a metre ruler can be used.2) using opisometer

Measuring curve lineMeasuring curve line using an opisometer

2) Measuring the diameter of object

External calipers Internal calipers

- The diameter of an object can be measured using calipers and ruler

- The external calipers is used to measure the external diameter of an object

- The internal calipers is used to measure the internal diameter of an object

Measurement area

Mark (/) on each square that is fully covered, half covered or more than half covered

12 unit2

a

b c

d

Measuring Volume of the object

30 ml

45 ml

stone

What is the volume of the stone?

= Water displacement method

Volume of the stone = (45 - Volume of the stone = (45 - 30)30) = = 15 cm15 cm33

Suitable for volume of uneven Suitable for volume of uneven objectobject

Measuring Volume object less dance than water

30 cm3

45 cm3Object x

load

55.5 cm3

What is the volume of x?

Volume of object x = (55.5 -45)Volume of object x = (55.5 -45) = = 10.5cm10.5cm33

Volume of stone

How to read the volume of liquid

Measurement SkillMeasurement Skill

1)1) The measurement is The measurement is accurateaccurate if it is very if it is very close to the actual valueclose to the actual value

2)2) Inaccurate measurement may lead a Inaccurate measurement may lead a scientific investigation to make a wrong scientific investigation to make a wrong conclusion to an experiment.conclusion to an experiment.

3)3) We can increase the accuracy:We can increase the accuracy:

a) using a) using suitable suitable measuring toolsmeasuring tools

b) using b) using right techniqueright technique – avoid parallax error – avoid parallax error

c) taking c) taking several readingsseveral readings – take the average – take the average