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Published by cfathanah, 2023-01-09 00:42:28

Nota Segak Science Form 4

Nota Segak Science Form 4

Alloy

Mixture of several types of metals or mixture of metal and non-metal by a certain percentage.
Alloy is stronger, harder, and resistant to corrosion.

atoms of pure metal

Atoms are same size, closely -
packed and orderly in layers.
When force is applied, the layers
of atoms easily slide over each
other.

alloy Atom of foreign element
Atom of pure metal
Atoms are different size and not
arranged in order.
When force is applied, the layers
of pure metal have difficulty in
sliding over each other.

Therefore, the hardness
increases.

When force is applied, the layers of
atoms in pure metal have difficulty

to slide over each other


Body of vehicles Railway tracks Duralumin

steel Body of Aluminium + Copper + Decorative items
aeroplanes Magnesium + Manganese
Iron + Carbon Pewter

Light, strong,
resistant to corrosion Tin + Copper
Hard & Strong
Buildings Shiny surface,
resistant to corrosion

Alloy

Monument Coins Doorknobs Keys

bronze Medals Musical brass
instruments
Copper + Tin Copper + Zinc

Hard, resistant to corrosion Strong, shiny surface, malleable


Glass Ceramic

Made of SILICA Made of clay (ALUMINIUM SILICATE).

Made from borosilicate Made from soda-lime Ceramic tiles. Durable, Ceramic dining ware.
glass. High resistance to glass. Easy to shape. sparkling & beautiful. Resistant to heat &

heat & chemicals. corrosion.

Transparent. Made from lead crystal glass. Dentures. Hard & Ceramic flowerpots.
High refractive index strong. Hard & strong.


polymer

Polymerisation Polymer is a long chain molecule formed from a
combination of small units of molecules (monomer).

Monomer Depolymerisation Polymer Synthetic polymer

Synthetic Monomer Uses
polymer
Natural polymer

Natural Monomer Uses Polythene Ethene Plastic containers
polymer Polystyrene Styrene
Container
Carbohydrate Glucose for electrical
equipment

Protein Amino Perspex Methyl Windows for
acid methacrylate vehicles

Natural Isoprena Synthetic Neoprene Tyres,
rubber rubber gloves


Soft & Natural rubber Good
Elastic electrical
Non-heat Properties insulator
resistant O f natural
Not
rubber permeable

to air

the action of acid & alkali on latex

Ethanoic Latex Ammonia Latex does
acid coagulate solution not
Latex coagulate
Latex

Acid will coagulate latex. Ammonia will prevent the coagulation of latex.
Positively-charged hydrogen ions from the acid will Hydroxide ions from the alkali will neutralise the hydrogen
neutralise the negative charges of the protein membrane. ions from the acid.
Rubber molecules will collide, protein membrane will Negative charges remain on the protein membrane. Rubber
break, chain of rubber polymer coagulates. molecules repel one another & remain in liquid form.


Vulcanised rubber

Vulcanisation of rubber

Process of heating rubber with sulphur.
Cross-links between sulphur and rubber polymer
chains prevent the molecules of rubber from
sliding & difficult to break when force is applied.

Resistant Good USES
to heat electrical
insulator Shoe soles

Harder Properties Does not Gloves
& more Of oxidise
elastic easily Car tyres
vulcanised
Not Rubber Does not
permeable react with
to liquid
acid &
& air alkali


Traditional medicine

Ginger GINSENG Quinine

Relieve body aches. Increase immunity. Treat malaria.

Relieve bloatedness. Maintain body health.

hibiscus plant Aloe vera

Relieve headache. Reduce pain due to sunburn.
Prevent hair loss.
Treat blisters/ scalded skin.


Complementary medicine

Acupuncture Chiropractic Traditional massage

To stimulate the nervous To make adjustments to Manipulates the body
system to relieve pain. the bone position. tissue using hands, fingers

and fist.

Homeopathy Herbal therapy

Give strengthens the Plants or parts of the plants that cure
body's immunity against diseases.

infectious disease.


Modern medicine

ANALGESIcs Antibiotics Psychotherapeutic

Relieves pain. Kills the growth of infectious bacteria. Treat psychiatric patients.

Example : Must be finished within the Need to follow the dosage
Aspirin prescribed duration to prescribed by the doctor -
Paracetamol ensure all the bacteria are can cause mood swings,
Codeine destroyed. thought disorder and
changes in a person's
Example : penicillin, behaviour.
streptomycin
Stimulants -stimulate & activate the brain
activity. Eg: amphetamine
Antidepressants - treat depression.
Eg: imipramine, amitriptyline
Antipsychotics- have sedative effects.
Eg: tranquiliser, barbiturates , doxepin dan
haloperidol


Traditional M odern Complementary
medicine medicine Medicine

Treatment using natural Uses modern Does not use medicine, drugs &
substances from plants and technology (surgery, synthetic chemical substances.

animals laser treatment, Does not involve surgery &
radiotherapy) stitches.

Inherited & practised from Treatment that uses Various methods of healthcare &
generation to generation synthetic medicine treating diseases

Effectiveness of the Treatment is more Additional treatment performed
treatment is slower & takes effective and faster with modern medicine to treat

a longer time High treatment cost diseases

Low treatment cost Low treatment cost

Effectiveness proven with Effectiveness is proven Considers the views of modern &

experience clinically traditional medical practitioners


factors that produce free radicals

internal factors external factors

Metabolism Cigarette
smoke

Toxic waste

Inflammation Ultraviolet
rays
free radical Air pollution
Ionising radiation
Causes DNA damage


effects of free radicals on human health

Free radicals Free radicals damage DNA structure, forms
atoms/ molecules that lack carcinogenic substances that may cause:

one electron (unstable,
reactive) and tend to attack

other atoms/ molecules.






mutation cardiovascular disease infertility
canser damage the kidneys, liver and premature aging conditions
lungs such as wrinkles and grey hair


Antioxidant substances oxidation on apple
(exposed to air)
antioxidants
Free
Chemical substances that are

needed by our body to slow down/ radical
stop the oxidation process.

Protects body cells from damage by Lime juice
free radicals. (antioxidant substance)

healthy can slow down the
body cell oxidation process.

examples of antioxidants

Beta carotene Lutein Lycopene Vitamin c Vitamin e

Most red,yellow or orange Often associated with Fruits. Papaya, Known as Known as alpha-
ascorbic acid.
coloured food. Carrots, healthy eyes. Green guava, tomato Citrus fruits, tocopherol.

manogoes, sweet potatoes. leafy vegetables spinach, Palm oil, wheat
strawberries,
germ oil, corn oil,
cereals.
soybean oil


active ingredients in health product

Active ingredients are specific components in a product
that have effects on the cure or prevention of disease.

benefit To restore and maintain our health.
To ensure normal growth and increase the body's immunity.
A necessity to maintain health while busy working.
As a complement to eating habits.

Be careful Choose suitable health products which are registered with the
when Ministry of Health, Malaysia (KKM).
Read and check the labels first to know the contents and how to
using health consume the health product correctly.
products Get the advice of medical doctors.


Distance - the Linear motion
total path length
travelled by an Displacement-the distance of the
object. shortest path that connects two locations
in a specified direction.
Distance = 80m + 120m
=200m Displacement = 144m in the northwest direction

144m

80m

120m

SPEED The rate of change of distance Unit = m/s
Unit = m/s
AVERAGE SPEED The rate of change of
VELOCITY total distance travelled Unit = m/s
Unit = m/s2
ACCELERATION The rate of change of
displacement

The rate of change of
velocity


types of Linear motion

Can be determined from the distance between dots on the
ticker tape.


Free fall non-free fall

Object falls due to the effect Object falls due to the effect of
of gravitational force only. gravitational force and
affected by air resistance,
Only occurs in a vacuum. mass or others.
(space with no air).

Same gravitational Different gravitational
acceleration depends on
acceleration no matter what mass and shape.

their mass and shape are. Example : In air, a feather Air
take a longer time to reach
Example : In vacuum, a VAcuUM the bottom compare to air resistance
tennis ball when released
feather and tennis ball will from the same height.

reach the bottom

simultaneously when

released from the same

height.

Time taken for the free fall object to fall is shorter than non-free fall
object.


Inertia

Natural tendency of an object to resist any change in its original state,
whether at rest or in motion.

original state of object at rest original state of object in motion

When the cardboard is pulled When a book is pulled
from a stack of books, the
quickly, the coin will fall into the other books above it will Inertia of the passenger maintains the
glass. The inertia of the coin will original state of passenger, that is, being in
maintain the original state of drop to the bottom. motion. Thus, the passenger continues his

the coin. forward motion.

the larger the mass of an object, the larger the inertia of the object.

Ali Abu

The mass of a trolley filled with things is Time taken to stop swinging for Ali Time taken to stop swinging for pail
larger, therefore its inertia is also larger. This is longer. that filled with sand is longer.
causes the trolley to be more difficult to move Mass of Ali is higher, inertia of Ali is
from its original state. higher Pail that filled with sand has higher
mass, so higher inertia.


effects of inertia in daily life

The loose head of a hammer can be A car is equipped with The chilli sauce in a bottle can be
tightened by banging its handle airbags, headrests and poured out easily by moving the bottle
against a hard surface. A swift bang safety belts to reduce the downward quickly with a sudden stop.
drives the hammer head downwards effects of inertia. (Inertia causes the chilli sauce to pour
due to inertia. out of the bottle)

A wet umbrella can be dried by During landing, an aeroplane of The tank of a tanker is divided into a few
spinning it quickly. Inertia causes the large mass cannot stop within a small components. Each component will
rain drops to fall from the umbrella short distance due to inertia. contain a smaller mass of petrol. A
even though the umbrella has Therefore, long runways are smaller mass has a smaller inertia, so the
stopped spinning. needed to land safely. impact of inertia can be reduced if an
accident happens.


Nuclear energy

Alternative energy that is used to generate electricity.

Greater quantity of energy and more efficinet.

Nuclear fission Nuclear fusion

uranium-235 nuclear energy Energy

neutron

Chain reaction - The nuclear fission will Process of combining two light
occur continuously when a neutron radioactive nuclei to form a heavier
bombards and splits a new nucleus of large nucleus and energy.
mass. Releases more nuclear energy than
nuclear fission.


nuclear power station

Turbine Electricity generator
The turbine is rotated by Generates electricity.
steam causing magnets in

the generator to spin

Boron control rods
Control the rate of
nuclear fission reaction
by absorbing surplus

neutrons

Graphite moderator
Slow down the neutrons

Uranium fuel rods Cooling agent Condenser Menara
Release heat energy Absorbs heat Cools and condenses pCoeonlyinegjutkokwaenr
through nuclear fission to produced by the
heat up gas flowing nuclear reaction steam into water
through the reactor core

Concrete shield
Prevent radioactive
radiation leakage from

the reactor.


effects of radiation
spread from nuclear test

somatic effects genetic effects

Tiredness Nausea Hair loss Deformation Cell mutation
in babies

Cataract Leukaemia Cancer


JUSTIFICATION FOR THE
CONSTRUCTION OF NUCLEAR POWER

STATION IN MALAYSIA

agree disagree

1.Alternative energy. 1.Improper disposal of radioactive
2.Nuclear energy is more wastes can cause environmental
pollution.
environment-friendly.
3.The cost of generating electricity 2.If exposed to radioactive
radiation can cause mutation
from nuclear energy is cheaper. and cancer.
4.Has a lot of usages in daily life.
5.The rate of energy generation 3.Requires a high cost for the
construction and maintenance of
from nuclear energy source is a nuclear power station.
higher compared to fossil fuel
energy sources. 4.Radioactive radiation leakage &
accidents can happen due to the
negligence & mistakes of
monitoring systems.


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