ANDREW CHOO EXAM TIPS SPM 2013 SCIENCE EXTRA NOTE FOR PAPER I FORM 4 CHAPTER 2 BODY COOERDINATION 2.2 Human Nervous System 3. Spinal Cord i. Protected by vertebral column. ii. Inside is grey matter consists of cell bodies. iii. Outside is white matter consists of nerve fibres (axons). iv. Spinal Cord a. Connect the brain with the rest of the body parts if damage would be paralyzed. b. Control reflex actions. 4. Synapse i. to connect two neurones together: a. sensory neurone to relay neurone b. relay neurone to motor neurone. ii. A tiny space that allow impulse to travel chemically from one neuron to another in one direction. 7. Voluntary actions Stimuli ↓ Receptor (nose, ear, skin, eye, tongue) ↓ Sensory neurone ↓ Brain (central nervous system) ↓ Motor neurone ↓ Effectors (muscle / gland) ↓ Response 8. Neurone / nerve cell - Is the basic functional unit of the nervous system. - To receive and transmit nervous impulses. a. Sensory neurones SPM 10
Transcript
ANDREW CHOO EXAM TIPS SPM 2013 SCIENCE EXTRA NOTE FOR PAPER I
FORM 4 CHAPTER 2 BODY COOERDINATION
2.2 Human Nervous System ����
3. Spinal Cord i. Protected by vertebral column. ii. Inside is grey matter consists of cell
bodies. iii. Outside is white matter consists of nerve
fibres (axons). iv. Spinal Cord
a. Connect the brain with the rest of the body parts if damage would be paralyzed.
b. Control reflex actions.
4. Synapse i. to connect two neurones together:
a. sensory neurone to relay neurone b. relay neurone to motor neurone.
ii. A tiny space that allow impulse to travel chemically from one neuron to another in one direction.
7. Voluntary actions Stimuli
↓ Receptor (nose, ear, skin, eye, tongue)
↓ Sensory neurone
↓ Brain (central nervous system)
↓ Motor neurone
↓ Effectors (muscle / gland)
↓ Response
8. Neurone / nerve cell
- Is the basic functional unit of the nervous system.
- To receive and transmit nervous impulses. a. Sensory neurones SPM 10
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- Transmit nerve impulses from
receptors to the central nervous system.
- Has a short axon b. Relay neurons ����
- Transmit impulse from sensory
neurone to motor neurone. - Connect sensory neurons with motor
neurons. - Found inside the central nervous
system / spinal cord. c. Motor neurons
- Transmit nerve impulse from the
central nervous system to the effectors which are muscle or glands.
- Have long axons to send nerve impulses to the effectors.
9 a. Cell body - Control and activity of the neuron.
b. Dendrites and Dendrons. i. Received impulses and ii. Send impulses to the cell body.
c. Axons - Carry nerves impulse along the nerve.
d. Myelin Sheath - Insulates, protect axon and speed up the
transmission rate of nerve impulses along the nerve fibre.
10. Kinaesthesis Sense SPM 08 a. contains proprioceptor / stretch receptors
found in muscle, ligaments, tendons and joints. i. To maintain the body balance and
coordination without looking at. ii. Detect the movement, change of
position, muscle stretching, contraction or twisting.
b. Example, i. Walking on rope by an acrobat ii. Buttoning shirt, cycling.
iii. Tying shoe string iv. Typing, clapping or walking up stairs. v. Estimate the weight or length of an
object
Proprioceptor
2.5 Differences between voluntary actions and involuntary actions. SPM05/12
Voluntary actions Involuntary actions - Under conscious control based on our needs.
- Learning is required.
- Not under conscious control (automatic).
- No learning is required.
- The same stimulus may lead to different response depending on
- The same stimulus always produces the same response.
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different situations. - Controlled by the cerebrum.
- Controlled by the medulla oblongata or spinal cord.
c. Cerebellum SPM 11 - Maintaining body posture, equilibrium or body balancing. Control contraction and relaxation of muscles.
d. Medulla Oblongata ���� - Controls in involuntary actions, e.g. heartbeat, breathing, circulation of blood, peristalsis, swallowing, growing, digestion and respiration.
- If injured, the person will die.
7. ���� Body Coordination
Nervous system Endocrine system a. SIMILARITY
i. Carry out body’s responses towards stimuli. ii. Both involve four component; stimulus, receptor, effector and response. iii. Coordinate all body activities and responses iv. Ensure survival of life
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b. DIFFERENCES i. Consists of the brain, spinal cord and
neurons / nerves. ii. In the form of electric impulses. iii. Comes from inside and outside the body. iv. Fast and often does not last long. v. Normally localized like the organs and
glands vi. No feedback mechanism.
i. Consists of endocrine / ductless glands and hormones in blood.
ii. In form of chemicals known as hormones. iii. Comes from inside the body. iv. Most of them are slow and long lasting. v. Normally widespread and covers the whole
body. vi. Has feedback mechanism and response.
6. Drug Abuse (Excessive use of drug)
a. Drugs is a chemical substance that can influence the function of the nervous system and the mind.
b. Types of drugs: i. Stimulants ii. Depressants
iii. Hallucinogen iv. Opiates
c. Effects of drug abuse on health i. Poor physical and mental health. ii. Affect the respiratory system, nervous
system, immune system and internal organ such as liver and the heart.
iii. Lost of appetite and malnutrition. iv. High risk at contracting HIV/Hepatitis
B because of sharing contaminated needles.
v. Suffer of vomiting, disease like pheumonia, bronchitis and flu as the immune system become weakened.
7. Alcohol SPM 03/06
a. Such as ethanol, a psychoactive substances which influences the central and peripheral nervous system.
b. Ethanol is produced by fermentation process of glucose by yeast.
Energy
dioxideCarbon Ethanol Glucose Yeast
++ →
c. Effect of excessive consumption of alcohol on body coordination. i. Effect the brain – loss of memory,
poor judgment of distance, double vision, loss of self-control and slurred in speech.
ii. Slow down the nervous system, coordination and movement slows down and become clumsy.
iii. Blockage in blood capillaries resulting in unconsciousness.
iv. Dehydration due to freaquent urine. v. Malnutrition because of loss of
appetite. vi. Cause obesity, heart disease, liver/
cirrhosis, gastritis/ulcers. vii. Retard of foetus or birth defect.
8. The importance of avoiding excessive consumption of alcohol a. Damage to the health. b. Causes accidents. c. Contribute to crimes, suicide or spousal
abuse. d. Leads to a breakdown in the family unity
and causing social problems.
9. Importance of a sound and healthy mind a. The mind controls how we think, feel and
react. b. Healthy mind enables a person to think
rationally, choose between the good and the bad, fair judgments to solve problems, generate new ideas and lead a happy and fulfilling life.
c. Factors that influence the mind : i. Excessive consumption of alcohol ii. Drug abuse
iii. Hormonal imbalance iv. Mental stress(insufficient of sleep,
mental anguish , overwork and sadness)
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v. Brain injury (cause memory loss, nausea, giddiness and disability)
vi. Physical health, mental health, emotional health, spiritual health and social activities.
FORM 4 CHAPTER 3 HEREDITY AND VARIATION 1. Chromosomes
a. Small thread-like structures exist in pairs which contain genes / DNA. b. Located in the nucleus of a cell. c. A human being has 23 pairs of chromosomes (46 chromosomes) which made of acid (DNA) and
protein. 2. Genes (DNA)
a. are base unit of hereditary materials located on chromosomes, which determine characteristics of a person.
b. exist in pairs.
c. Genes / DNA Dominant Recessive
- called dominants traits which show the characteristic /traits when paired with a dominant or a recessive gene.
TT = tall Tt = tall
- which show recessive traits when both genes are recessive.
tt = short
4. a. Type of chromosomes (46) Autosomes Sex 22pairs 1pairs = 44 = x / y
Autosome Sex Total Male 44 + xy = 46 Female 44 + xx = 46
b. Chromosomes in Gametes
sperm = 22 + x / 22 + y ovum = 22 + x c.
5. Sex determination- by the chromosome in sperm - The probability of having a male or female
child is the 50% because half of the sperms carry y chromosome and half of other sperms carry x chromosome (Ratio 1 : 1)
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9. Mutation ���� a. is the sudden change to the structure of genes or number of chromosomes b. can be caused by mutagen such as
i. chemical substances (e.g. pesticide, nicotine in cigarettes, drugs, nitrogenous acid, preservatives, colouring or artificial sweetener)
ii. radiation (gamma ray, ultraviolet, x-ray) iii. temperature (too high or low)
c. Advantages i. cause variation to enable organism to adapt to the environment (more resistant to diseases,
weather or pollutant) ii. creation of new species.
d. Disadvantages - cause diseases (colour blindness, haemophilia, anaemia or klinefelter’s syndrome, polydactyl trait)
Hereditary Diseases caused by
e. Mutation Gene ���� f. Mutation Chromosomes ���� - change in the structure a gene in
the chromosomes x of the recessive gene by mutagen.
- eg. a. albinism b. haemophilia (blood unable
to clog) c. anaemia. d. colour blindness (unable to
differentiate between red and green)
- changes in the number of chromosomes by mutagen. i. eg. Down’s syndrome (has small eyes and square
face) (47 chromosomes) presence of one extra chromosomes at the 21st pair of chromosome.
ii. Klinefelter’s syndrome (has small testis and sterile) (47 chromosomes) presence of one extra x ( 44 + xxy) chromosome at the sex chromosome (xxy in the male)
iii. Turner’s syndrome (45 chromosomes) lacks one x chromosome (xo in the female) (44 + ox).
10. Genetic Engineering is to improve the quantity and quality of Crops / livestock a. In Medicine - to identify heredity / sex – linked disease. b. In Agriculture- : i. Improve the quality of breeds ii. Bring in new species with higher resistance to disease or pests or environment iii. Increase production
11. Medicine ���� - Most heredity disease like colour blindness, haemophilia and albinism are caused by recessive
genes or sex linked genes (x chromosomes).
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12. Agriculture
a. Selective breeding or cross-bred to produce new varieties which have better characteristics. Example :
i. Oil palm Pisifera and Dura to produce Tenura which bear more fruits, thinner shell and more oil content.
ii. Artificial insemination where good semen from male animal is placed into the body of female animal for fertilization
iii. Embryo transfer of good breed to the uterus of a female animal. iv. Cloning of produce offspring that similar to its parents.
Body Health - Food containing certain nutrients required by
the body can be produced Better quality of crops and livestock - Better quality of crops and livestock can be
produced. Quantity can be increased - Crop and livestock that grow faster can be
produced. Conservation of environment - The use of pesticides can be reduced with the
Nutritional value of food - Genetically modified food may not have
the same nutritional value Effects of new genes - New genes in food may be transferred in
human body. Such genes may affect functions of human cell.
Long –term effects - New species of crops and livestock which
adapt better to the change in the environment might cause authentic
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production of crops which have high resistance to disease or pests.
species to become extinct.
FORM 4 CHAPTER 4 MATTER AND SUBSTANCES
1. Matter - Has mass and occupies space - Exists in the states of solids, liquids and gases.
2. Kinetic theory of matter states that a. matter is made up of tiny and discrete particles. b. particles always moving in random motion and collide against one another (Brownian
movement). c. the moving energy of particles is called the kinetic energy of particles. d. kinetic energy influence by the temperature of the matter. (Temperature↑= kinetic energy ↑) e. particles in an element are similar
3. SPM 10
SPM 10
Solid Liquid Gas - Particles are arranged closely and orderly in fixed positions.
- Cannot be compressed. - Vibrates at their fixed positions.
- Attraction forces are very strong
- Kinetic energy is very low
- Particles are not orderly arranged
- Cannot be compressed. - Particles keep contact with one
another with spaces between particles.
- Move freely - Attraction forces is weak. - Kinetic energy is higher.
- Particles are further apart
- Move freely in random in all direction.
- Attraction force is very weak and compressible.
- Kinetic energy is the highest.
4. Sublimation �
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- process where solid changes to gas or gas
to solid without going through the liquid. - e.g. iodine, dry ice, ammonium chloride
and naphthalene. 5. Diffusion
- can occur because particles move into the space in between the particles of solids,
liquids and gases. - eg: when 50 3cm of ethanol and 50 3cm of
distilled water are mixed, only 98 3cm of mixture are obtained. This is because the ethanol and water particles occupy each other spaces between the particles.
6. Brownian motion - Is random movement example shown by
smoke particles or pollen grains when knocked about by air particles.
7. Changes in the state of matter SPM 05
Graph about heating of substance
Graph about cooling of substance
7b. c. AB
- The particles absorb heat and vibrate faster. Kinetic energy increases and the temperature rise.
PQ
- The particles release heat. The kinetic energy decrease and the temperature drop.
BC - Melting point (fix temperature when solid becomes liquid)
- The solid particles have enough energy to break away from the rest. The temperature does not rise because the energy absorbed is used to break the force of attraction between the solid particles to form liquid particles.
QR - Condensation point - The gas particles lose energy and
become nearer to form liquid. The temperature does not drop because the energy is released to increase the force of attraction between the gas particles to form liquid particles.
CD SPM 05
- Completely melt and the kinetic energy increase causing the temperature to rise.
RS - Completely become liquid and the kinetic energy decrease causing the temperature to drop.
DE SPM 05
- Boiling point (fix temperature when liquid becomes gas)
- The liquid particles have enough energy to break away from the rest. The temperature does not
ST - Freezing point - The liquid particles begin to arrange
themselves orderly and turn into solid.
- The temperature does not drop
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rise because energy is absorbed to break the force of attraction between the liquid particles to form gas particles.
because the energy is released to pull the liquid particles together to form solid particles.
EF - Completely boiled to become gas. The kinetic energy increases cause the temperature to rise.
TU - Completely solidify into solid state, - The temperature drops to room
temperature because the kinetic energy decrease.
8. Atom (a basic unit of all matter) SPM 09 - all matter consists of tiny units called atoms
Subatomic Charge Relative mass Proton +ve 1 unit
Neutron neutral 1 unit Electron -ve 1/1840 unit
9. a. Neutral atom is the number of protons equal to the number of electron b. Ions are atoms which have charges.
i. Positive ion = atom which losses of electrons (Number of electron < proton) ii. Negative ion = atom which receives more electrons (Number of electron > proton)
�
14. a. Characteristic or Properties of Metals and Non-Metals SPM 12
15. a. Experiment: To study the effect of impurities on the freezing point of distilled water.
Metal Non-Metal SPM 12 a. Shinny and lustrous b. Ductile; can be pulled into a wire. c. Malleable; can be beaten into thin sheet because atoms in
metal can slide over one another easily. d. Tensile; very strong because of strong metallic bonding. e. Good conductor of electricity because of free electrons. f. Good conductor of heat. SPM 08 g. Very dense because atoms in metal are closely packed. h. Very high boiling and melting points because of very strong
atomic / metallic bonding. i. e.g. iron, gold, copper, aluminium, zinc. j. Aluminium is used as food wrapper .���� k. Gold is used to make jewellery because malleable (easily slide
over one another), shinny and non-rusting. ����
a. Dull b. Brittle or fragile and breaks
easily c. Not malleable d. Weak and snaps easily e. Insulator f. Poor conductor of heat g. Low density h. Low boiling or melting
points because of weak Van der Waal force.
i. e.g. sulphur, glass, chlorine, sulphur.
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i. Variables Manipulated : presence of salt Constant : volume of distilled water Responding : reading of the thermometer / freezing point
ii. Definition of distilled water – Distilled water is pure water that freeze at 00C iii. Definition of impure water – Water that contain dissolve substances that freeze at -20C iv. Inference : Salt can lower the freezing point of distilled water. v. vi.
Conclusion : Impurities can affect the freezing point of distilled water. Definition of freezing point: is the reading of the thermometer.
b. Pure Substances SPM 03/05 i. Distilled water is pure water because it does not contain any dissolve substance or foreign
matter. ii. The boiling point of pure water is 1000C and melting point is 00C. iii. However impurities such as salt can increase the boiling point to 1020C and lower the
melting / freezing point to -20C. iv. Ice-cream hawkers add salt into the ice box to lower the melting point of ice to prevent the ice
cream from melting too quickly. v. Workers add salt on the road during winter to prevent the snow from melting too quickly.
16. Experiment : To study the effect of impurities on the boiling point of distilled water SPM 10
i. Variables
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Manipulated : presence of salt Constant : volume of distilled water Responding : reading of the thermometer / boiling point
ii. Definition of distilled water – Distilled water is pure water that boil at 1000C iii. Definition of impure water – Water that contain dissolve substances that boil at 1020C iv. Inference : Salt can increase the boiling point of distilled water. v. Conclusion : Impurities can affect the boiling point of distilled water.
17. a. Purifying Substances Distillation (to obtain pure liquid ) ����
- Is the process of boiling the liquid and condensing the vapour into pure liquid .
Liquid
Gas Liquid
Distillation of ethanol
Note: Mixture of water and alcohol can be separated by distillation as they have different boiling point. (Alcohol has lower boiling point than water)
b. Crystallisation (to obtain pure solid / salt / sugar) SPM 04 - Is forming of pure sugar crystal from a hot saturated solution of a sugar when it is cooled. - e.g. mining salt (sodium chloride) from sea water / obtaining sugar from sugar solution / solid
copper sulphate. Obtaining pure salt crystal
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FORM 4 CHAPTER 5 ENERGY AND CHEMICAL CHANGES
1. a. Physical change (changes in appearances) SPM 05
b. Chemical change (changes in chemical properties) SPM 05
- No new substance formed - Chemical property remains the
same - Reversible - Little energy is required - Alters the form / appearance - Examples: ����
i. melting, condensation ii. boiling, sublimation iii. solubility, freezing iv. evaporation, dissolving v. crystalisation
vi. distillation
- Form new substance - Different from original - Involves absorption / release of heat - Irreversible - Plenty of energy required - Chemical property changes - Examples: ����
i. Burning of paper / petrol / magnesium / aluminium
ii. Rusting of iron / respiration iii. Change in colour of sliced apple / digestion iv. Neutralization, decomposition v. Heating iron with sulphur vi. Heating copper carbonate / zinc carbonate vii. Putting calcium into water
2. Heat change in Chemical Reaction SPM 09 a. Exothermic reaction
(releasing heat to form bond) b. Endothermic reaction
(absorb heat to break bond) - Surrounding temperature increase
- Examples: Temperature of the solution rise when Sodium hydroxide crystals dissolve into water i. magnesium ribbon is burned in air ii. calcium hydroxide or zinc reacts with dilute
hydrochloric acid iii. concentrated sulphuric acid is dissolved in
water
- Absorb heat to break bonds. - Surrounding temperature lowered - Examples: i. solid Ammonium Chloride is
dissolved in water ii. solid Potassium Nitrate dissolved
in water iii. reaction of Zinc and Copper
Sulphate 3. Reactivity Series of Metals a.
Very reactive
Potassium Sodium Calcium Magnesium Aluminium
React with water
React with steam
to produce alkali + hydrogen
Less reactive
Zinc Iron Lead Tin Copper
React with acid → salt + hydrogen
React with oxygen → metal oxide
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Non-reactive
Mercury Silver Platinum Gold
Free pure elements
b. Metal + Water / steam → Alkali + Hydrogen Magnesium + Water → Magnesium hydroxide + Hydrogen Aluminium + Steam → Aluminium oxide + Hydrogen * more reactive metal produce more hydrogen
c. Reactivity of metal with acid SPM 03/07/11/12
SPM 07
Relationship: The volume of gas increase with time.
Metal + Acid → Salt + Hydrogen Zinc + Sulphuric acid → Zinc sulphate + Hydrogen
Iron + Hydrochloric
acid → Iron chloride + Hydrogen
Extraction of ore by
b. i. Electrolysis Process
- Metals which are located higher than carbon in the reactivity series can be extracted using the electrolysis process. These metals are more reactive than carbon therefore can’t use reduction method of carbon.
- e.g. aluminium is extracted from the bauxite ore by electrolysis. b.ii. Extraction of metal by carbon located below carbon in the reactivity series are extracted by
the reduction method by carbon, such as Zinc, Iron, Tin, Lead, and Copper. SPM 09
a. Potassium Sodium Calcium Magnesium Aluminium
Extraction by electrolysis only because these metals are more reactive than carbon.
Carbon Zinc
Iron Lead Tin Copper
Extraction by reduction method by carbon because these metals are less reactive than carbon. Carbon is chosen because it is cheap, economical and easily available ����
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Tin Oxide + Carbon → Tin + Carbon dioxide (cassiterite) (coke) (pure)
Blast Furnace
c. The reactivity can also be used to forecast whether a particular metal can extract another oxide. For example, aluminium which is located higher than lead in the series is more reactive. Therefore, it can remove oxygen from the lead oxide
Aluminium + Lead oxide → Aluminium oxide + Lead
Electrolysis Break compound into its elements using electricity (Electric energy → Chemical energy)
1 a. Electrolysis of Copper Chloride Solution
Anode Cathode
- Chloride gas is produced./turn damp litmus paper into red
- Chlorine ions release electrons to become chlorine atoms
- CleCl →−−
- Copper is deposited. - Copper ions receive electrons to become copper atoms
- CueCu →+ −+
b. Electrolysis used for ���� i. Extraction of metals iii. Electroplating of metals ii. Purification of metals
Note: Advantages of using carbon is: i) economical ii) easily available
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2a. Extraction of Metals ( Aluminium from bauxite) ����
c. Electroplating of Metals (Electroplating iron nail with copper)
**Note: Copper (ll) sulphate solutions colour unchanged because the copper ions that deposited onto the cathode is replaced by copper ions that dissolved from the anode.
i. The aims / advantage of electroplating: a) Prevent the metal from corrosion (rusting) b) Make the metal look more attractive ii. The following methods should be taken into consideration to obtain a good quality and
attractive electroplated product. a) The surface of the metal to be plated must be clean by sand paper beforehand. b) Electric current supplied should not be too big c) Dilute electrolyte should be used. d) The period of electroplating should take a longer time.
e) The nail must be rotated slowly. iii. The metal used in anode must same with the metal compound solution. iv. The electrolyte must has same type of metal ion with the anode
Note: Cryolite is added to lower the melting point of the bauxite.
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Electrical Energy from Chemical Reaction 1. Simple cell SPM 04 (Chemical energy → Electrical energy)
i. The less reactive metal like copper is made the positive electrode (anode).
ii. The more reactive metals like zinc is made the negative electrode (cathode) because this metal is more likely release electrons to form ions.
iii. No electricity is produced when both metals are the same.
iv. The further the metals apart, the higher the voltage/current is produced.
2. Cells Primary Secondary
- Non-rechargeable. - eg:
a. dry alkaline battery (used in torch light) b. silver-oxide mercury battery (used in
watches/calculators)
- Rechargeable. - eg:
a. lead acid accumulators (used in car) b. nickel-cadmium battery (used in
handphone)
3. a. Dry Cell/Alkaline bateries – used in torch light / portable radio.
i. Ammonium chloride paste as electrolyte. ii. Carbon powder to reduce the resistance.
iii. Manganese oxide to oxidizes the hydrogen gas produced into water to reduce the polarisation of the cell.
b. Advantages of dry cell - non-spill over - small light and portable.
c. Disadvantage - non- rechargeable. - short life span.
4. Lead - Acid Accumulator (rechargeable) used in car.
Advantages - produce a stable current - produce higher voltage - rechargeable - last longer Disadvantage - can spill over - it is heavy
c. Electroplating of Metals (Electroplating iron nail with copper) SPM 06
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**Note: Copper (ll) sulphate solutions colour unchanged because the copper ions that deposited onto the cathode is replaced by copper ions that dissolved from the anode. �
i. The aims / advantage of electroplating: a) Prevent the metal from corrosion (rusting) b) Make the metal look more attractive ii. The following methods should be taken into consideration to obtain a good quality and
attractive electroplated product. a) The surface of the metal to be plated must be clean by sand paper beforehand. b) Electric current supplied should not be too big c) Dilute electrolyte should be used. d) The period of electroplating should take a longer time.
e) The nail must be rotated slowly. iii. The metal used in anode must same with the metal compound solution. iv. The electrolyte must has same type of metal ion with the anode
Chemical reaction that occur in the presence of light/Photosynthesis Reaction
1. Photographic paper
Silver bromide →light Silver(darker) + Bromine gas
Formation of Image by Optical Instruments 1. Mirror
- Periscope in submarine, double-decker bus or too see over the wall.
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2. Convex lens a. Magnifying glass
b. Telescope – the image is at infinity, virtual
and inverted. – 0ffe <
c. Microscope – the final image is virtual, inverted and enlarged. - eff <0 d. Human eye – image formed are real,
inverted, and diminished. i.
ii.
e. Camera - amount of light entering a camera
depends on: i. The size of the aperture (diagram). ii. The shutter speed.
- Image formed: i. real, ii. upside down (inverted)
iii. smaller size (diminished) iv. shorter image distance
3. Comparison between Human Eyes and Camera. Human Eyes Camera i. Eye lens convex lens ii. Iris diaphragm iii. Pupil aperture iv. Retina film v. Ciliary muscles focusing ring
4a. Light Dispersion Using Prism SPM 04/10
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i. White light disperses because white light
consists of different light colours. ii. which travel at different velocities
iii. refracted at different angles when dispersed by a glass prism.
b. When the spectrum is combined, a white light is produced
c. Natural phenomena of dispersion of light/ spectrum..
i. Rainbow � ii. Soap bubbles
5. Light colour SPM 10/12
a. Primary colours - Original colour that can’t form by any
combination of light colours. - Red + Blue + Green = White
b. Secondary colours � - consists of two primary colours combined
together. i. Red + Blue → Magentha ii. Red + Green → Yellow
iii. Blue + Green → Cyan
6. Colour filter . SPM 05/10/11/12 a. Only allow light colour which is same
colour to pass through. b. Other colours are absorbed
7. Colour object � a. Only reflect light colour which is same
colour with the object b. Other colours are absorbed
Primary + Primary → Secondary
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8. Phenomenon of Scattering of light SPM 11 a. Sky looked blue
- The blue, indigo and violet lights are scattered by air molecules to the sky causing the sky looked blue.
b. Sunrise / sunset looked reddish in colour
- The blue, indigo and violet lights are scattered by air molecules. Only red and yellow lights reach our eyes make the sunset / sunrise looked reddish in colour.
9. Formation of rainbow (light dispersion)
- After raining, the water droplets in the atmosphere act as glass prism and dispersed the sunlight to form a spectrum of light called rainbow.
10. Important of colour �
- make peacock has colourful feather to attract mate
- lizard can camouflage itself same colour as surrounding colour
- to protect themselves from enemy.
FORM 4 CHAPTER 8 CHEMICAL IN INDUSTRY
10. The control of industrial waste can be carried out by:
i. Law enforcement such as ban on open burning
ii. Education / Awareness campaigns. iii. Use of technology in treating industrial
waste such as a. Fix electrostatic precipitator / air
filter - To filter smoke / soot / dust in the
chimney/coal ashes - The filtered coal ashes can be used
to process fertilizer. b. Scrubber
- A liquid spray to dissolve poisonous gases such as nitrogen dioxide / sulphur dioxide.
c. Direct burning
- Agricultural industrial wastes are directly burned in a heating furnace and thick smoke is filtered.
- The heat produced can be generated electrical energy.
d. Biogas technology - Agricultural wastes like palm oil
wastes are decomposed by microorganisms. The methane gas produced is used as fuel / electrical energy. The sludge left can be used as fertilizer.
e. Disposal drums - Made of strontium to keep
radioactive wastes like uranium / plutonium deep below the soil surface ocean.
f. Chimney
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- Using tall chimney to disperse smokes.
g. Incinerator
- burn waste products inside incinerator to prevent releasing of toxic gases
11. Types of pollution Effect Solving Method Air pollution Lungs cancer
Asthmatic - Use electrostatic precipitator in chimney - Ban open burning - Burn in incinerator
Water pollution Cholera - Enforcement of laws - Recycling the waste - ‘Love our river’ campaign
FORM 5 Chapter 1 Microorganisms and Their Effects on Living Thing
1.1 5 Groups of Microorganisms / Microbes 1. Bacteria
i. unicellular ii. with cell wall
iii. do not have nucleus iv. some can move with flagella. v. reproduce by binary fission or
conjugation vi. when condition unfavourable, it
becomes spore. Spores can only be destroyed by heat over 120°C in an autoclave.
vii. some bacteria has chlorophyll to make own food but some are parasites or saprophytes.
b. 4 types of bacteria according to its shape. i. Spherical
ii. Rod-shaped
iii. Comma- shaped
iv. Spiral / Spring – shaped
2. Fungi �
i. Reproduce by spores like mucor or budding like yeast.
ii. Do not have chlorophyll / cannot make food by photosynthesis.
Fungi Unicellular Multicellular
- such as yeast, mucor or penicillium
�
- such as mushroom
Fungi Saprophytic Parasite
eg: mucor feeds on decaying organic matter.
eg: ringworm sucks nutrients from the living organism.
3. Protozoa - unicellular - eg: amoeba and paramecium. - Reproduce by binary fission
amoeba paramecium
4. Viruses
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a. smallest microorganisms that can pass
through filter. b. come in many geomical shapes. c. are living things because they:
i. can reproduce ii. have nucleic acids
d. are not living things because they: i. do not respire, feed or excrete ii. can be crystallized when the condition
is unfavourable. e. can only reproduce in a living host cell
(parasite) f. cannot be destroyed by antibiotic.
5. Algae (green plant / producer) �
- Contain chloroplast and can make own food by photosynthesis.
- Reproduce by binary fission, fragmentation or conjugation.
Algae Unicellular Multicellular
� Euglena
Chlamydomonas
Pleurococcus
Spirogyra
Seaweeds Hydra
1.3 Uses of microorganisms � 1. Food digestion
a. protozoa / bacteria that live in the alimentary canal of herbivores such as rabbit / cow produce cellulose enzyme to digest cellulose.
b. bacteria in human large intestine help to digest food and produce vitamin K / B12. 2. Decaying process / putrefaction / decomposition
a. bacteria / fungi decompose dead organisms into simple molecules to be returned to nature / be recycled (to maintain the carbon-cycle).
b. Bacteria are also used to decompose organic waste such as oil palm / paddy wastes to produce methane gas.
3. Medicine a. Bacteria / fungi can produce antibiotics and vaccines. b. antibiotic from bacteria / fungi can be used to treat diseases caused by bacteria.
Antibiotic can treat diseases caused by bacteria Penicillin gonorrhea, syphilis and pheumonia Streptomycin tuberculosis Tetracycline respiratory tract, syphilis and acne.
c. However, antibiotics are not effective against viruses or cure diseases caused by virus such as Aids / Hepatitis, cold and Dengue.
4. Agriculture a. Putrefying bacteria / fungi adds humus and improves the fertility of the soil. b. Nitrogen – fixing bacteria found in the root nodules of leguminous plants provide the plants with
nitrates. c. Microorganisms are also used in biological control to eliminate pests, example,
i. Bacterium to destroy beetles. ii. Virus to destroy rabbits.
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5. Industry a. Food industry
- Example: � i. Alcoholic drinks
- wine, beer, brandy - Yeast carries out fermentation on glucose to produce ethanol.
ii. Bread, cake - Carbon dioxide is produced during fermentation of yeast. These carbon dioxide bubbles make the dough rise so that the bread is soft.
iii. Cheese, cream, yogurt & butter
- Bacteria / fungi is used to ferment milk into cheese, butter, yogurt and cream.
iv. Soy sauce - Yeast v. Vinegar - vi. Tea leaves -
b. Rope industry c. Leather industry d. Cleansing
eg: Purify petroleum and mineral ores (bacteria are used to eat up the impurities)
1.4 Harmful effect of microorganisms a. Pathogens - Are microorganisms that are harmful and cause diseases. b. Tooth decay
(caries) - The bacteria in the plaque act on the food residue to produces lactic acid
which corrodes the tooth. c. Food
poisoning - Food that contaminated by microorganisms that produce toxins which
cause illness. - Symptoms include nausea, vomiting, abdominal pain and diarrhoea
8. Diseases � Pathogen Diseases Symptoms
Tuberculosis (T.B)
Chest pain, cough, fever, night sweats, fatigue, weight loss, shortness of breath, loss of appetite, coughing up blood.
a. Bacteria
Cholera Vomiting, severe diarrhoea, dehydration of body, stomach cramps.
Gonorrphea Discharge of pus from the genitals, painful urination. Veneral disease
Syphilis Fever, swollen lymph nodes, lesions throughout the body, patchy hair loss on the head.
b. Fungi Tinea or ringworm Ring-shaped infection on the skin, red and scaly patches that itch.
c. Protozoa Malaria Bouts of high fever, sweating and shivering, nausea, muscle pain.
Common cold Sneezing, runny nose, fever, sore throat, fatique, headache, general aches and pain.
Dengue fever Headache, high fever, severe pain in joints and muscles, sore throat, skin rashes.
Hepatitis Fever, jaundice (yellowing of the skin), dark-coloured urine, weight loss
d. Viruses (can be cured by antibiotic or vaccine)
AIDS (Acquired Swollen lymph nodes, infections by bacteria, viruses and fungi,
a. Infection through air /droplets - are known as airborne diseases which affect the
respiratory system such as tuberculosis, common cold and pheumonia.
- Covering the nose/mouth when sneezing/coughing.
- Do not split. - Avoiding crowded area. - Home is brightly lit and airy.
b. Infection through water - Waterborne diseases which affect the digestive system
such as cholera, typhoid fever and amoebic dysentery. - Spread through water that contaminated by faeces of
infected person, carcase or poor sanitation system.
- Improving sanitary system. - Drink boiled water. - Adding chlorine into tap water.
c. Infection through food - Food contaminated by houseflies, cockroaches or dirty
hand.
- Covering the food. - Wash hands after using the
toilet. - Cook food thoroughly.
d. Infection through contact - Spread of Aids by HIV viruses through direct contact
such as sexual activities, sharing of syringe, blood transfusion or mother to baby during delivery.
- Tinea/Ringworm and white spot through indirect contact of sharing towels, clothes, shoes or combs.
- Maintaining one’s personal hygiene.
- Avoid sharing personal belongings such as towels, shoes.
3. Infection through vectors - Vectors are animals or insects that transfer pathogens.
- Eliminate the breeding grounds of vectors.
10. Pathogens – microorganisms that cause disease. 11. Vectors – insects or animals that carry pathogens that cause disease.
Vectors Diseases a. Aedes mosquitoes carry virus Dengue. b. Anophelcs mosquitoes carry protozoa Malaria c. Culex mosquitoes Japanese encephalitis (JE) d. Houseflies and Cockroaches carry
bacteria Food poisoning such as cholera, typhoid fever, amoebic dysentery, food poisoning.
e. Fleas Typhus, bubonic plague. 12. Controlling the breeding of mosquitoes. �
Life cycle of mosquitoes Ways of controlling a.
Egg - Mosquitoes lay eggs in stagnant
water such as ponds, clogged drains and flower pots / old tyres which hold water.
- Eliminate these breeding grounds. - Unclogged the drain to clear the
stagnant water. - Containers / old tyres which hold
water should be buried.
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Larva - Feeds on algae in the water. - Breathe through the water surface.
- Raring guppies / fish to eat up the larvae or pupae (a biological control method that never harm the environment).
b. i.
ii .
Pupae - Breathe through a pair of breathing
tubes on the water surface.
- Adding oil onto the water surface to prevent larvae / pupae from breathing.
c.
Adult mosquitoes - Only female mosquitoes suck
human blood. - It secretes saliva to prevent clotting
of blood. - The pathogens enter the human
body together with this saliva.
- Cutting down bushes / tall grass to eliminate the hiding place of mosquitoes.
- Carry out fogging / spraying insectides.
- Sleep under a mosquito net or cover windows / doors with wire gauze.
Life cycle of houseflies � Ways of controlling
d.
Housefly - Mature female housefly lays eggs
in rubbish dumps / faeces / food that left exposed.
e.
Egg - It will hatch within a day to
become larva. f.
Larva / Maggots - Within five days turns into pupae.
g.
Pupa - Undergo metamorphosis and turn
into housefly in three days.
1. Get rid of breeding grounds such as rubbish dumps and exposed faeces / food.
2. Rubbish bins should be covered. 3. Build more hygienic toilets with
flush facility. 4. Food should always be covered.
13. Sterilisation � - Ways of sterilization:
Sterilisation a. Sterilisation by heat b. Sterilisation by chemicals c. Sterilisation by radiations
i. Cooking food to kill microorganisms.
ii. Boiling water 100°C to kill microorganisms such as boiling feeding bottle.
iii. To kill the spores, an autoclave / pressure cooker is used to achieve 120°C.
i. Antiseptics are chemicals used to kill microorganisms on the skin / wounds such as dettol, burnol or iodine which do not kill the tissues.
ii. Disinfectants such as chlorox, formalin and chlorine which are stronger chemical used to sterilise buildings, toilets, utensils or clothing.
i. Using gamma rays to sterilise drugs, vaccines or surgical instruments.
ii. Using ultraviolet to sterilise mattresses or pillow.
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14. Treating diseases caused by microorganisms a. Antibiotic (penicillin)
- Obtained from bacteria / fungi to kill /inhibit the growth of other microorganisms.
- Disease caused by bacteria or fungi such as Tuberculosis, Cholera, Gonorrhea, Syphilis, Tinea or ringworm can be treated by antibiotic.
- However, antibiotic is not affective against diseases caused by virus such as Cold, Hepatitis, Dengue or Aids.
b. Antifungal drugs - To treat diseases caused by fungi such as athlete’s foot and ringworm. c. Vaccine - Weakened / dead pathogens (bacteria / fungi) that can stimulate the
white blood cells to produce antibodies when injected into the body. d. Antibodies - Produced by the white blood cells when the body injected with vaccine=
can fight pathogens e. Serum - Animals’ antibodies which give immediate immunization when injected
into the body. (Artificial Passive Immunization) f. Chemotherapy - Can be in the form of lotion to apply on the skin or taken through the
mouth. g. Radiotherapy - Using radioactive rays to treat skin diseases, tumours and cancer. h. Surgery - To remove seriously infected organs that drugs failed to treat. i. Vaccination - Injected the body with vaccine dose.
15. Dangers of using drugs without prescription and medical advice a. The course of antibiotics taken must be completed to ensure that all the pathogens are killed. b. Any pathogens that left behind may lead to a reoccurrence of the diseases. c. The antibiotics may lose its effectiveness as the pathogens has build up resistance. d. Taking too much / often antibiotics will kill the friendly bacteria in our alimentary tract and affect
our digestive system. e. Antibiotics may cause allergies to certain people, e.g.: cause rashes, swelling, inflammation, heart
palpitations or death. f. Some drugs must be taken on an empty stomach and some be taken after meals.
FORM 5 CHAPTER 2 NUTRITION AND FOOD PRODUCTION
NUTRITION AND GOOD EATING HABIT
1. Calorific value. - Is the energy content of a food / energy
produced when 1 g of food completely burnt in air.
- Can be measured by using a Bomb Calorimeter.
2a. Calorific value of � i. Carbohydrates = 17.2kJ-1g ii. Protein = 22.2kJ 1g− iii. Fats = 38.5kJ-1g (2 x carbohydrates)
(highest calorific value)
1 calorie = heat required to rise 1 g of water to 1°C
Vegetables, vitamins, water and minerals do not contain any energy at all.
FORM 5 CHAPTER 3 PRESERVATION AND CONSERVATION OF THE ENVIRONMENT
1. Natural cycles include a. Nitrogen cycle b. Carbon cycle c. Water cycle
2a. Nitrogen cycle
Atmospheric nitrogen Death
animals / plants
Decomposition (Putrefaction)
Ammonium compound
Lightning
Denitrifying bacteria
Nitrogen fixation (Nitrogen – fixing bacteria in root nodules)
Nitrates in the soil
Nitrifying bacteria
b. Carbon cycle
c. Water cycle
Atmospheric carbon dioxide
Respiration
Photosynthesis
Animals Plant
Combustion
Fossil / wood
Decomposes
Death
Respiration nutrition
Death
Decomposition (microorganism) dead organisms
condensation Cloud Water Vapour
Evaporation
Respiration
Transpiration
Rain
Pond / river / sea →drink Animals Plants
3. Food Chain - is transfer of energy from the producer to consumers. �
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Sunlight (main source of energy)
Nitrates (Simpler Molecules)
Paddy (producer) can make food by photosynthesis
Death
Worm (primary consumers) Death
Chicken (secondary consumers) Death
Eagle (tertiary consumers) Death
Decomposes (bacteria / fungi)
4. a. Food web - is the interaction of a few food chains.
b. Pyramid number
5. Natural disaster disrupts the natural cycles and food web.
12. Effects of Greenhouse effect / Global
warming � a. sea levels increase due to iceberg melting
at the poles of the earth b. droughts which causes low yield of crops
and famine 13. Carbon monoxide
- from exhaust fumes of vehicles can reduce intake of oxygen to the brain.
14. Sulphur dioxide, carbon dioxide and nitrogen dioxide can cause acid rain which carrode buildings and roof-top.
15. (Euthrophication Process) Excessive chemical fertillser can dissolve into rain water and flow into pond cause algae to grow. When algae dies, it decays and reduces the amount at oxygen and cause the fish to die.
16. Ways to solve green house effects - Reforestation/tree replanting - Ban open burning - Reduce vehicles on the road / practice car-
pool system
FORM 5 CHAPTERS 4 Carbon Compounds 1. Carbon Compounds �
Natural disasters Effects i. Volcanic eruption - Change the physical condition of the earth. ii. Earth quake - Destroy the organism and their habitats. iii. Drought - Disrupts the food web.
iv. Flood - Causes soil erosion and landslides. v. Typhoon - Destroy buildings, habitats, death.
vi. Forest fire - Destroy habitats.
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a. Carbon – is a non-metallic element but conduct electric. b. Carbon
Diamond Graphite – hardest form of carbon – used to make jewellery – can cut glass
– soft and slippery – Used to make pencil’s lead
Carbon Compounds
Organic SPM 11 Inorganic c.
- Derived from living things (plants / animals) - Contain a lot of carbon atoms - e.g. 6126 OHC .
- Dissolve in organic solvents such as ether, alcohol, petrol or chloroform.
- Has low melting or boiling points. - e.g. alcohol, sugar, fats, protein, fossil fuels or
hydrocarbon (petroleum, coal, natural gas).
- Derived from minerals in the earth. - Contains few carbon atoms - e.g. 2CO . - Dissolve in inorganic solvents such as
water, acids and alkalis. - Generally more stable with high melting
/ boiling points. - e.g. carbon dioxide, copper carbonate,
calcium carbonate / lime stone / marble. 2. Hydrocarbon SPM 07 a. Consists of hydrogen and carbon
elements only. b. Natural sources of hydrocarbons are fossil
fuels such as: i. Coal ii. Natural gas such as ethane, butane,
propane…. iii. Petroleum
c. Petroleum i. Contains a mixture of hydrocarbons. ii. Can be separated by fractional
distillation because each hydrocarbon has different boiling points.
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iii. Fraction of petroleum and its uses. Fraction Main uses
1. Petroleum gas - Fuel for cooking and making plastic.
2. Petrol
- Fuel for motorcycles, cars and aeroplanes (vehicles).
3. Naphtha
- Fuel for airplanes and making synthetic rubbers / candle.
4. Kerosene
- Fuel for jet planes and kerosene lamps and for making detergents.
5. Diesel - Fuel for diesel engines and boilers. 6. Lubricating oil
- Engine lubricant and to make polish.
7. Fuel oil
- Fuel for ships and electrical generators.
8. Paraffin - For making wax and polish. 9. Bitumen
- For covering roads and as a coating for underground pipes.
Earlier fractions Lower boiling point Less dense / lighter Less viscous Less yellowish Less carbon / soot Better fuels
Later fractions More dense / heavy
More viscous More brownish More carbon / soot Higher boiling points
7. Uses of alcohol a. Ethanol is used to make alcoholic drinks
such as beer, wine, brandy and whisky. b. Organic solvents for shellac, inks,
perfumes, cosmetics, or medicine such as cough mixture.
c. Disinfectant to kill microorganism e.g. is rubbed on skin before an injection is given.
d. Antiseptics such as iodine solutions. e. Ether is used to prepare artificial flavours. f. As fuels, burn completely without soot. g. Methanol to prepare formalin for
preservation. h. To make ethanoic acid / vinegar. i. Thermometric liquid to measure
temperature.
8. Effects of excessive consumption of alcohol on health
a. cause nervous system slows down. b. Become drunk, poor body coordination and
cause accidents. c. Damage the stomach, liver (cirrhosis),
kidneys and heart. d. cause addiction and social problems. e. cause retardation to foetal growth.
9. Fats is molecule of Glycerol and Fatty acid. � - Consist of carbon, hydrogen, and oxygen.
- Provide double energy than carbohydrate. - As insulator for our body. - Solvent for vitamins A, D, E and K. - Excessive cause obesity and raise the level
of cholesterol.
SPM 11
Fats Saturated Unsaturated
- contains maximum hydrogen atoms. - Mainly animal fats. - Solid in room temperature. - Raise the cholesterol level. - Higher melting point. - e.g. butter, cheese, ghee, meat…..
- still can receive hydrogen atoms - Mainly plant oil. - Liquid form in room temperature. - Cholesterol free - e.g. palm oil, corn oil, peanut oil, soy oil, olive
oil …….
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10. Hydrogenation process
19. Natural Rubber / latex
a. Polymer latex is formed from monomer isoprene
b. Properties of rubber / latex i. soft, low melting point, not resistant to
heat ii. elastic, insulator to electricity
iii. dissolves in organic solvents such as benzene or carbon disulphide
20. Action of Acid on Latex / Rubber
SPM 09/12
Coagulation of latex liquid
latex / rubber +
formic acid
→ coagulate latex / rubber
a. Rubber is consists of polymer molecules
which is surround by a protein membrane which is negative charged.
b. These negative charged repel one another and prevent the rubber molecules from coagulate.
c. When acid (formic acid) is added, positive charged hydrogen ions from the acids neutralize the negative charges on the protein membrane.
d. When the rubber molecules collide one another, the protein membranes break
e. The rubber molecules are released and combined to coagulate
Acid added +H hydrogen ion
21. When it is kept for a long time, bacteria in
the air can produce lactic acid which coagulates the latex as well
22. Ammonia or any alkali solution can be added to latex to prevent coagulation because negatively charged hydroxial ions of ammonia solution can i. neutralize any positively charged hydrogen
ions from acids that presence ii. prevent the growth of bacteria.
23. Vulcanisation of rubber a. Natural rubber which is soft, easily
stretched and cannot withstand heat can be vulcanised with sulphur to be more hard, elastic, resistant to heat and stronger.
b. Vulcanised rubber is used to make i. tyres ii. rubber hose iii. basket ball iv. Shoe sole
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c. Vulcanisation Process
+
Natural rubber Sulphur atoms Vulcanised rubber
- soft - not heat resistant
- Sulphur atoms crossed-links between the rubber molecules to prevent it from sliding over one another.
- Become harder, heat resistant and more elastic.
- Used to make tyres, rubber hose or basket ball.
FORM 5 Chapter 5 MOTION SPEED, VELOCITY AND ACCELERATION
1 a. Speed 1−== msTime
Distance
� b. Velocity 1−== mstaken Time
direction withDistance
c. Acceleration - is change of velocity per unit time
- Acceleration taken Time
velocity of Change= taken Time
velocity Initial -velocity Final=
1−=−= ms
t
uva �
2. Ticker – Timer
Ticker Tape Pattern Interpretation Graph a.
Direction of motion
Uniform distance between two consecutive dots
Uniform speed or uniform velocity
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Direction of motion
Distance between dots increases uniformly Speed or velocity
increases - increasing
velocity
b. c.
Direction of motion
Distance between dot decreases uniformly
Speed or velocity decreases - decreasing
velocity
MOMENTUM Momentum = mass × velocity � Momentum = m × v
= kg × ms-1
a. i. ( momentum ↑ = mass ↑ × velocity ) Mass increase � momentum increase
ii. ( momentum ↑ = mass × velocity ↑ ) Velocity increase � momentum increase
iii. Hypothesis The bigger the mass / velocity, the greater the momentum.
b. Conservation of momentum i. During collision the total momentum of
the system remains unchanged. ii. Total momentum = Total momentum
before collision after collision
c. Types of collisions i. Inelastic collision ( bodies stick together
after collision)
m1u1 + m2 u2 = (m1 + m2)v
ii. Elastic collision (bodies separate after collision)
m1u1 + m2 u2 = m1v1 + m2v2
d. Applications of Momentum
i. Pile driver (has high momentum due to big mass)
ii. Bullet fired from a gun (has high momentum due to high velocity)
iii. Steam roller ( has high momentum due to big mass)
iv. Rocket - The exhaust gases from the combustion
chamber of a rocket escape from the back with great force.
- This creates a great momentum backwards.
- This backward momentum creates an equally big forward momentum, which pushes the rocket forward (This uses the principle that every action creates an equal and opposite direction)
e. Safety Measures in Motor Vehicles i. Force = rate of change of momentum
takenTime
momentum of Change=
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takenTime
momentum Initial - momentum Final=
Force F = t
mu - mv
ii. F ↓ ↑
=t
mu - mv
Note: Force is reduced, when time taken is increased
f. Parts of the motor are specially designed to increase the time taken in order to reduce the force.
i. has front and rear crumple zones to absorb force.
ii. has soft bumper to increase the time of collision
iii. has air bags / safety belt to reduce the impact.
iv. Bumpers – Soft to increase the time of collision to reduce the force
Motion of Vehicle in Water
Type Picture Characteristic Ship
- A small ship may be driven by a diesel engine. - A large ship is driven by a steam turbine. - In a steam turbine, steam under high pressure pushes
the fixed blades and rotates the drive shaft. - The rotating drive shaft spins the propeller of the
ship. When the propeller spins and pushes the water backwards, a forward momentum of equal force is produced. This forward momentum or thrust pushes the ship forward.
- A ship also has a rudder. This rudder controls the direction of motion of the ship.
Hovercraft
- A hovercraft moves on a cushion of air on the surface of the sea.
- A powerful engine produces a cushion of air between the surface of the sea and the bottom of the hovercraft. This reduces greatly the friction between the water and the bottom of the hovercraft. This enables the hovercraft to move forward speedily.
- The large fans on top of the hovercraft produce a strong backward wind. This creates an equally strong forward momentum which pushes the hovercraft forward.
Hydrofoil
- A hydrofoil has special wing-shaped structures, called hydrofoils, attached to the lower surface.
- When the boat moves forward at a high speed, the hydrofoils below the boat are lifted slightly above the surface of the sea.
- This decreases the friction between the surface of the sea and the bottom of the boat.
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- With less friction, the boat is able to travel much faster.
2. Streamlined shape a. Enable object to move easily in water with little resistance (reduce friction) b. eg : fish , ship, torpedo and etc.
Archimedes’ Principle SPM 12
Upthrust force = weight of the object = weight of water displaced = mg = pvg
Upthrust = weight – weight
on air in water = 0.8 – 0.6 = 0.2N
Note: Denser water such as seawater which contain salt produce bigger upthrust. The denser the water, the greater the upthrust / the lighter the object float. Application of Archimedes’ Principle 1. Plimsoll line
- show how much the ship can be safety loaded when sailing in the sea 2. Submarine SPM 08
- A submarine has ballast tanks. The submarine becomes dense and submerged in the sea when the ballast tanks are filled with the sea water.
- The submarine becomes less dense and rises to the surface when the ballast tanks are emptied.
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Picture Characteristics
Aircraft
- When an aircraft is in flight, the shape of its wings causes air to move faster above the wings than below the wings. This creates slower pressure above the wings. Air pushing upwards on the wings produces a lift (upward force).
- When an aircraft is flying with a uniform velocity at affixed height, then:
Hot air balloon
- The hot air inside the balloon is less dense than the atmospheric air.
- The weight of air displaced by the balloon is heavier than the weight of the balloon and its hot air.
How Jet Engine Work
Structure of a jet engine
i. Air is sucked into the compressor ii. The compressor compresses the air into very hot air iii. In the combustion chamber the kerosene fuel is
sprayed into the hot air iv. The mixture of hot air and fuel will burn with
explosive force and produce a great backward momentum.
v. According to conservation of momentum an equal forward momentum is produced and pushes the jet forward.
vi. A jet plane uses oxygen from the atmosphere and can’t fly beyond the atmosphere. It never carries its own supply of oxygen.
Rocket Engine
Structure of a rocket engine
i. A rocket carries liquid hydrogen and liquid oxygen. ii. They are burned with great explosive force in the
combustion chamber. iii. Hot exhaust gases produce a great momentum
downward. iv. According to the conservation of momentum, this
produces an equal great momentum upward which push the rocket upwards.
v. Rocket can move beyond the atmosphere because it carries its own supply of fuel and oxygen.
vi. A rocket travels with increasing acceleration because - air resistance decreases with high and zero at
outerspace.
Thrust = drag Lift = weight
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- gravitational attraction decrease with height. - the rocket’s mass decrease as the rocket’s body is
shedded by stages Application of Bernoulli’s Principle SPM 10 1. Aerofoil
i. The high speed of air moving above the aerofoil produces a low pressure. ii. The slower speed of air moving below the aerofoil produces higher pressure. iii. The differentiate of pressure cause an uplift force on the aerofoil.
2. Other apparatus using Bernoulli’s Principle SPM 10 a. Bunsen burner b. Filter pump c. Insecticide spray
Bernoulli’s Principle - States that the pressure decreases when the speed of fluid / gas increases.
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Bernoulli Effects
Diagram Activity and observation Reason
Blow hard across the surface of a sheet of paper held horizontally in front of the mouth. This causes the paper to rise.
The air moving across the top of the paper at a fast speed causes a region of low air pressure above the paper. Atmospheric pressure below the paper pushes the paper upwards.
Blow air at a fast speed down the filter funnel. The ping pong ball does not fall.
The air pressure in the space above the ball is lowered because of the fast flowing air. Atmospheric pressure which is greater pushes up the ball and supports it.
Hang a ping pong or polystyrene ball near a fast stream of water from a tap. The ball is attracted towards the water.
The fast moving stream of water produces a region of low air pressure around it. Atmospheric pressure being greater, pushes the ball towards the water.
FORM 5 Chapter 6 Food Technology and Production
1. The purpose of processing food a. to kill microorganisms. (preserve the
food) b. extend the shelf life of the food
/making the food last longer c. adding nutrients to the food.
d. Making the food looked attractive, delicious and easier to digest.
e. making the food easier to be stored and transported.
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CHAPTER 7 SYNTHETIC MATERIALS IN INDUSTRY
1.a. Polymer is along chain of molecules / monomers that are combined together. � b. Natural polymer are latex (isoprene), starch, protein and cellulose.(from plants/animal)
c.
2. Comparison �
Natural rubber Synthetic rubber Similarities
- Both are carbon compounds - Insulator to electricity - Both exist as polymers
Differences - Very elastic - Less elastic - Not so airtight / permeable - Airtight / non-permeable - Low heat tolerance - High heat tolerance
- Good absorber of sound and pressure - Poor absorber of sounds and pressure
- Easy to vulcanize by sulphur atoms - Difficult to vulcanize by sulphur atoms
- Easy to oxidise / unstable - Difficult to oxidise / stable
i. multicasting of sending message to unlimited end-users. ii. least disturbance or interference iii. provide wide coverage and live telecast iv. low cost of maintenance
