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Senior Science Notes 2015

Lifestyle Chemistry:
9
...
1 – The use of a substance depends on its physical and chemical
properties
...

o Detergents
o Lubricants
o Pesticides
o Solvents
o Metal cleaners
o Cosmetics
o Body hygiene chemicals
● Identify that solutions, colloids and suspensions occur in a wide range of
customer products
...
g
...

o Colloids: cloudy mixtures with particles that remain suspended for long
periods of time – in a colloid the particles of one substance are scattered
evenly throughout another – e
...
oil in water mixtures, water in oil mixtures,
gas in liquid mixtures (foamy products such as whipped cream, shaving
cream) and liquid in liquid mixtures
...
Since there is a insoluble substance in the solvent, it quickly settles
down and forms layers at the bottom of the container – e
...
sand in water,
dirt in water, pebbles in water etc
...

- Suspensions contain particles that settle out, or form layers quickly
...
The two or more substances that
make up the mixture cannot be separated by filtration
...
g
...

o Suspensions: The particles in a suspension are large enough to be seen by the
naked eye
...
It can be filtered by filtration – e
...
solid particles suspended in a
liquid (copper carbonate in distilled water), liquid suspended in another liquid
(fresh milk)
...
Examples include:
- Liquid in liquid: homogenized milk, mayonnaise
...

- Solid particles in a liquid: paint
- Solid or liquid particles in gas: water vapour, smoke
...

o There are weak cohesion forces that holding the particles of a liquid together
...

o Comparing droplets of mercury and water, mercury has a much stronger
cohesion force between its particles than water, which allows it to be in a
more spherical shape than water
...

o Surfactants are chemicals that reduce the surface tension of a liquid
...
2
...

● State the relationship between the properties of an emulsion and the types of
molecules present
...
They are used to moisturise
or protect the skin and hair by placing oil onto the surface
...
These are miscible with water
...
The types of surfactant molecules present in oil-in-water
based emulsions are large molecules with very polar chemical groups at one
end
...
The other nonpolar end of the surfactant is attracted to the non-polar oil molecules
...

o Oil-based (water-in-oil) emulsions, such as cold creams, night creams and
hair creams, contain some water
...

They are useful to cleanse the skin, moisturize very dry skin and hold hair in
place, but are greasy and sticky to the touch
...
The chains wind among minute water droplets and
prevent them from merging together
...

o The molecules in emulsifying agents that are used in dishwashing and
laundry detergents (anionic) have a negative end when they dissolve
...

o The molecules in emulsifying agents that are used in fabric softeners and hair
conditioners have a positive end when they dissolve (cationic)
...

o The molecules in emulsifying agents that are used in personal cleaning
products are amphoteric, which means they can have positive ends in
alkaline solutions and negative ends in acidic solutions
...
However, they are not strong
cleaners
...

o Emulsifying agents reduce the difference in surface tension between the two
substances
...

o Soap and detergent is an emulsifying agent or emulsifier – soap causes grease
to be taken up by water as an emulsion and washed away
...

o Soaps and detergents are surfactants because they act at the surface between
two immiscible substances – e
...
oil and water
...

o Cleaning gents must be surfactants because they interact at the interface
between the two immiscible substances, allowing them to mix, creating and
emulsion
...

They cause the drops of oil to break up and remain suspended in water
...

o The role of the emulsifying agent is to ensure that the oil stays with the water
particles and not sticking onto anything else – e
...
the sides of a glass jug etc
...

o The term biodegradable is applied to those substances that can be
decomposed by micro-organisms and bacteria
...

o Soap is commonly the sodium or potassium salt of a natural long chain fatty
acid
...

o Soap-less or synthetic detergents were originally made from aromatic
compounds that produced good cleaning agents – however those compounds
were not biodegradable and this resulted in foam clogging up drainage
systems
...

They have a slight advantage over soaps in the way that they are effective in
hard water and cold/soft water
...
2
...


● Identify the role of the skin as:
- An organ to separate the body from the external environment
...

- An organ that protects against entry by disease-causing organisms
...

- The stratum corneum (makes up a part of the epidermis) consists of the
dead skin cells that have died from lack of food and oxygen
...

- The skin also protects the veins and other important organs inside our
body from damage
...


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Senior Science Notes 2015

In response to increased temperature, small blood vessels in the skin
dilate, increasing the blood flow to the skin allowing the excess heat to be
lost through radiation
...

- In response to decreased temperature, blood circulations through the
skin decreases and the blood vessels contract to move the heat further
away from the surface of the skin
...

o The skin as an organ that protects the body from disease causing microorganisms:
- The outer layer of the epidermis forms a barrier against bacterial
invasion
...

- The film on the surface of our skin contains a mixture of sweat, sebum
and micro-flora
...

● Define the term ‘micro-flora’ and discuss the role of the micro-flora on skin in
different parts of the body
...
These micro-floras live
harmlessly on our skin
...

o Micro-flora includes: bacteria, fungi, algae, protozoa and viruses
...
Staphylococcus aureus can cause serious disease if it
-

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Senior Science Notes 2015

gains entry to the bloodstream during medical procedures
...

● Discuss the term ‘pH’ in terms of its ability to describe the acidity of a
substance
...
A
substance is acidic because it contains free hydrogen ions
...

● Explain the relationship between the natural pH of the skin and the action of:
- Micro-flora
- Natural oil produced by the glands in the skin
- Perspiration
o Sebum: the natural oil produced by the sebaceous glands in the skin – it is
slightly acidic
...
Sweat produced by heat is more acidic than sweat
produced by exercise
...
Microflora can withstand the acidity of our skin (which is about 4 – 6) however
other harmful bacteria usually can’t survive this harsh environment so our
skin is able to protect us effectively
...

● Identify and explain the use of common components of body soaps, cleaners
and shampoos and the reason for their use
...

o Surfactants are needed to assist water to attach to oil particles – this includes
sebum that is produced by the sebaceous glands
...

o Oils: after removing the oil that had been contaminated by dirt, oils in the
cleaning products replaced the natural oil that had been removed
...

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Senior Science Notes 2015

o Fragrances and dyes: appeals to the consumer
...
Soap is made by reacting sodium hydroxide with an
animal/vegetable fat (e
...
coconut oil)
...
Cleansers dissolve sebum and loosen
particles of grime and dirt trapped in the pores of the skin
...
Common components include coconut oil, some
olive oil (coconut oil and olive oil = Palmolive), alcohol, glycerol and water,
detergent or soap and perfume
...


9
...
4 – the nature of a solvent plays an important role in the application
of a mixture
...

o Water and alcohol (ethanol) are commonly used as solvents for products that
are applied to the skin and/or ingested by people
...

o Alcohol is a solvent that can dissolve both non-polar and polar substances
because it is a polar and non-polar substance itself
...

● Explain the relationship between the properties of a solvent and their use in
cosmetics and external medications
...
Products such as
antiseptic solutions used alcohol as a solvent because of its ability to dissolve
some components that are insoluble or immiscible in water
...

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Senior Science Notes 2015

o Water: is used as a solvent for hair shampoo, moisturizing creams,
conditioners and hair gels
...

However there are some substances that are insoluble in water but soluble in
alcohol
...

● Identify cosmetics and external medication where alcohol is the solvent
...
Alcohol evaporates quickly from the mixture
and leaves the solute on the skin or nails – e
...
nail polish
...
Note: Alcohol is capable of dissolving both polar and non-polar
substances
...


9
...
5 – the solubility of materials used in drugs has an effect on the way
in which a body responds to them
...

o Mouth:
- Food is broken into small pieces, mixed with saliva and the digestion of
starch begins
...

o Stomach:
- Muscular layer churns and mixes food
...

- Protein digestion begins here
...

o Pancreas:
- Secretes pancreas juice
...

- Digestion of fats, carbohydrates and proteins
...

o Large intestine:
- Absorption of water and substances dissolved in water
...

● Outline the role of the stomach and small intestines in breaking down food
...
It does this by churning the food with gastric juice
...

o The small intestine produces enzymes that complete the digestion process
...
In the first section of the small intestine, called the duodenum,
the partly digested food is mixed with bile and pancreatic juice
...
The pancreatic
juice helps to break down carbohydrates to simple sugars, helps to complete
the digestion of proteins and to break down fats into fatty acids
...

o Discuss the differences in pH of the stomach and small intestine
...
The low pH allows the stomach to kill the harmful bacteria and
allows the enzyme pepsin to begin breaking down the proteins present in the
food
...

o Bile from the gall bladder emulsifies the fat present in the food
...

o When drugs are being designed, scientists consider carefully where in the
digestive tract the drugs should be dissolved, ready to be absorbed into the
bloodstream
...
It may have been
dissolved but it must still be chemically effective
- Is released within an appropriate timeframe
...

o Soluble tablets will dissolve rapidly in water producing a liquid solution
...

This is useful when fast-acting medication is desirable
...

o Drugs that dissolve in acidic solutions will be absorbed through the lining of
the stomach and are then taken to other parts of the body by the
bloodstream
...

o Medication may be designed especially to dissolve in the intestine rather
than the stomach
...
Some drugs are broken down in the presence of acids
and this may alter their effectiveness
...
For example,
some common drugs used in the treatment of arthritis are enteric-coated to
prevent their solution in the stomach, where they may cause irritation or
gastric upset
...

o Medication may be designed to dissolve over a period of time in order to
provide access to the drug without further ingestion
...

o The absorption of a drug can be affected by its solubility
...
A drug must be stable enough to survive the body's digestive
system
...

o Drugs taken orally may be soluble in water, soluble in alcohol or not soluble
in either
...

o Some drugs are prepared as sprays to act directly on the surface of the throat
or nose, or to be absorbed through the lining
...
This type of administration can be very fast-acting
...
Some sprays are very fine
particles of powder; others are a fine mist of dissolved particles
...
They include creams (water-based)
and ointments (oil-based), as well as gels, lotions (which may be water- or
alcohol-based) and liniments (usually alcohol-based)
...

o Highly soluble drugs can be easily carried in the bloodstream and so can act
more quickly on the body
...

o Depending on the rate of solubility of different drugs, different means of
administration are more appropriate
...

o Different ways of administering a drug include:
- By mouth: for absorption by the stomach or small intestine
...

- As a skin or dermal patch: for absorption by the skin
...

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Senior Science Notes 2015

As suppositories: for absorption by mucous membranes of the rectum or
vagina
...

- By drops: for absorption by the affected area only – e
...
eye and ear
droppers
...

o Water – soluble vitamins are: B1 (thiamine), B2 (riboflavin), Niacin, B6
(pyridoxine), pantothenic acid, biotin, B12, folate (folic acid); and vitamin
C
...

o Fat – soluble vitamins are: A, D, E; and K
...

-

Medical Technology –
Bionics
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Senior Science Notes 2015

9
...
1 – increases in scientific understanding and technological advances
have broadened options for maintaining humans as functioning
organisms
...

- They’re almost always made from metallic alloys
...

- Screws are used to fix bone plates to the bone and are some of the most
widely used device for repairing fractures
...

o Artificial joints:
- These replace joints that have been largely destroyed by degenerative
diseases such as arthritis or badly damaged in an accident
...

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Senior Science Notes 2015

Artificial hip joints are often made from stainless steel – polyethylene or
cobalt – chromium alloy – polyethylene combination
...

- Other joint replacements – fingers and ankles – have not been successful
due to the complexity of the movement of these joints
...
It is a battery operated device
...

- Pacemakers can be internally implanted or externally implanted
...

o Artificial valves:
- Heart diseases can lead to narrowing or leakage of heart valves
...

- Faulty heart valves can be replaced with biological valves from a human
donor or from a pig’s heart (since pigs are closely related to humans)
...

- Most artificial valves have a fabric ring surrounding them, allowing the
surgeon to sew the device into place during implantation
...
Artificial valves are constructed
from collagen-rich materials, such as pericardial tissues which have been
-

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Senior Science Notes 2015

obtained from pigs or cows and treated (to remove animal proteins and
minimize the risk of the tissue being rejected from the body)
...

o Crowns and dentures:
- Dentures are artificial teeth
...

- Problems with dentures: they are not particularly stable, they do not
always look natural; they allow the jawbone to absorb substances
...

- Crowns have traditionally been constructed from ceramic materials,
which have relatively low strength – however the development of metalceramic crowns has led to an increase in strength
...

- Cataracts are caused by the lens of the eyes growing cloudy and
eventually becoming opaque
...

- Cataract surgery involves replacing the damaged or cloudy lens with an
intraocular lens
...
Tiny platinum,
titanium, or gold loops are sometimes used to hold the lenses in place
...

Foldable lenses are made from either silicone or acrylic
...
Artificial body parts are
also called prostheses
...
Computers are now used to
design tailor-made models for amputees
...

- Modern prosthetic limbs often incorporate electronics and pneumatic
mechanisms of considerable complexity
...
It is used to
replace a damaged cochlea
...

- The cochlear implant works by converting sound into electrical impulses,
which can be used to stimulate the auditory nerves, sending a signal to
the brain which then creates a hearing sensation
...

● Gather and process information from secondary sources to trace the historical
development of one of the following implants:
- Cochlear implant
- Artificial valves
o Artificial valves:
- The first implantable artificial valve was invented in 1952, it was not until
the invention of the heart-lung machine, however, that surgeons could
safely enter the heart and repair or replace parts
...
The valve was made from a steel cage enclosing a silicon
rubber ball
...

- The development of implants followed attempts to produce hearing by
stimulating different parts of the auditory system with electricity
...
3
...

● Explain the relationship between the structure and functioning of the
following parts of the heart:
- Valves
- Atria
- Ventricles
- Major arteries and veins
o Valves:
- Structure present in the heart and in the veins that allow blood to flow in
one direction and not go back where it came from
...

o Atria:
- Function is to receive blood from the veins before passing it on to the
ventricles
...
The first beat of a heartbeat cycle is the
contraction of the atria pushing the remaining 20% of the blood into the
ventricles
...

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Senior Science Notes 2015

The function of the ventricles is to pump the blood away from the heart,
either to the lungs for re-oxygenation (right ventricle) or to the body for
distribution to the cells (left ventricle)
...

o Major veins and arteries:
- Arteries carry the blood away from the heart and veins carry blood back
to the heart
...

- There are two major arteries: the aorta and the pulmonary arteries – the
aorta takes blood from the left ventricle to the blood vessels that go to the
rest of the body
...
Two main arteries called the coronary arteries lead
from the aorta to supply the heart muscle itself with blood
...

o The small mass of specialized cells/tissues within the heart coordinates and
regulates the contractions of the cardiac muscle
...

o The electrical signal starts in the sinoatrial node, after the impulses starts it
quickly travels from cell to cell in the muscles of the atrium; causing it to
contract just before the ventricle does
...
As the impulse moves through, the chambers relax
...

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Senior Science Notes 2015

o Problems that can result from the interruptions to the normal rhythm of the
heart include an irregular heartbeat called arrhythmia
...

o Fibrillations are a type of arrhythmia
...

o A heartbeat that is too slow or slower than usual may cause fatigue, lightheadedness, or fainting
...

o Fibrillations in the ventricles is life threatening and may be resolved by
electric shocks
...

● Identify that a pacemaker will produce a regular electrical pulse
...

o The stimulator of the pacemaker produces an electrical current, which is
transmitted down conducting electrodes
...

o The pacemaker delivers an exact amount of electrical current to the heart at
varying heart rates
...

o The material used to construct pacemakers must be biocompatible (material
that won’t affect the body negatively), inert (doesn’t react with the chemicals
in the body), non-toxic and able to be sterilized
...

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Senior Science Notes 2015

o With a leaky or faulty valve, the heart must work harder which can cause a
heart attack or death
...
Symptoms of a
faulty valve include shortness of breath during exercise, tiredness, a continue
cough and occasional chest pain
...
Rheumatic fever (an autoimmune disease initiated by a bacterial infection) is the most common cause
of this type of valve damage, particularly the mitral valve
...

o Pyrolytic carbon is used mainly as a coating in the manufacture of artificial
body parts
...

- It possesses greater elasticity than graphite, an alternative material
...

- It is not prone to lipid absorption or swelling in the body, and
therefore may be used as a coating on the ball or disc in artificial heart
valves
...

o Teflon (polytetrafluoroethylene) is a polymer used in the manufacture of a
wide array of artificial body parts, including blood vessels, hip sockets and
soft tissue prostheses, such as ear and nose replacements
...

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Senior Science Notes 2015

- It is elastic, porous and strong
...

o A healthy artery and/or vein have a pale, smooth, glistening wall
...

o A fat deposit known as an atheroma is built up from cholesterol that is taken
in from the blood as low density lipoproteins
...

o The blood platelets (known for initiating clotting in blood) selectively adhere
to the rough surface and a blood clot (thrombus) subsequently forms
...

o Atherosclerosis of the coronary artery may lead to a heart attack if not
treated promptly
...

o Bypass surgery: this involves taking a vein from the patient’s leg and using
it to construct a new pathway for blood to flow around the blocked vessel
...
Body cells
(fibroblasts) invade the artificial structure and eventually it becomes
‘normal’ tissue
...
This was initially done
during bypass surgery
...
A catheter
containing the laser is pushed under the skin
...

A small cut is made into the arm or groin, a thin plastic tube is inserted into
an artery and pushed to the blocked blood vessel
...

When the balloon is inflated it pushes the plaque against the artery wall and
the diameter is widened
...

Extras:
● Structure of the heart:

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Senior Science Notes 2015

9
...
3 – the wide range of movements, continual absorption of shocks and
diseases make the skeletal system vulnerable to damage but new
technologies are allowing the replacement of some damaged structures
...

o The axial skeleton is made up of the skull, backbone and rib cage
...

o The appendicular skeleton is made up of the pelvic girdle, shoulders, arms
and legs
...

o Apart from support and protection, the skeleton also serves to:
- store mineral salts, such as calcium and phosphorus
- Produce blood cells in the marrow
...

o Ball and socket: allows movements in many directions
...

o Hinge: movement is restricted to one plane only like the hinge of a door –
examples include the elbow, knee and finger joints
...

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Senior Science Notes 2015

●

●

●

●

o Sliding: also known as gliding joints, they allow the sliding movement in all
directions because the opposing bones are flattened or slightly curved –
examples include some of the joints in the spinal bones and the tarsal bones
of the foot
...

Describe the role of cartilage and synovial fluid in the operation of joints
...
This allows for
smoother movement
...

o Synovial fluid: synovial joints are enclosed by the synovial membrane
which produces synovial fluid to lubricate the joints
...

Identify the properties of silicone that make it suitable for use in bionics
...
Some are completely insoluble in water, some allow the diffusion of
oxygen and because they contain no carbon, they are less likely to be
rejected by living tissue
...

o Silicone joints are suitable substitutes for small joints in the fingers and toes
that carry little weight because silicone can be bent and stretched many,
many times without breaking
...

Describe the properties that make ultra high molecular weight polyethylene
(UHMWPE) a suitable alternative to cartilage surrounding a ball and socket
join in terms of its:
- Biocompatibility with surrounding tissue
- Low friction
- Durability
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Senior Science Notes 2015

o UHMWPE is a suitable alternative to cartilage surrounding a ball and socket
joint due to its biocompatibility with surrounding tissue (the surrounding
tissue would not reject it), durability (it can be bent many, many times
without wearing away) and low friction which allows ease of movement
...

o The ends of artificial joints have their ends covered in polyethylene because:
it has similar density to living tissue, it is relatively elastic (especially high
density polyethylene), has a low coefficient of friction; it has low creep
properties – meaning it will not deform under stress
...

● Describe the properties of materials such as ‘super alloy’ that makes a ball and
stem for the bone components of a large joint including:
- High strength
- Low weight
- Good compatibility with body tissue
- Inertness
o Super alloys are made from metals
...

o The resulting properties include high strength, low weight, good
compatibility with body issue and inertness
...
Describe the properties of the cement that is used in implants and
discuss how uncemented implants form a bond with bone
...

o Cement free implant: designed to wrap around the remaining bone after the
diseased part has been removed
...
The expected time before a patient can walk
with cement free implant is longer than that of cemented implants
...
In early hip replacements
the shaft of the artificial hip was glued in place
...

o How uncemented implant forms a bond with the bone: uncemented
implants are hammered into place
...


9
...
4 – life support systems can be used to sustain life during operations
or while the body repairs itself
...

The trachea has C-shaped rings of cartilage that stop it from collapsing
...
Each bronchus leads to a
lung
...
The bronchi are divided into smaller tubes called bronchioles
...

o Alveoli: are highly folded micro-structures
...
The
highly folded structure of the alveoli provides a large surface area for
efficient gas exchange
...

o Capillary network around the alveoli: the capillaries are fine blood vessels
that transport high oxygenated blood from the lungs to the pulmonary vein
so it can be taken to the heart and pumped around the body; and low oxygen
blood from the pulmonary artery to the lungs for exhaled
...

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Senior Science Notes 2015

o Cardio-pulmonary (heart-lung) resuscitation (CPR) is a combination of
expired air resuscitation and external cardiac compression
...

o CPR prevents brain damage by keeping vital organs supplied with oxygen
...

o In the heart-lung machine, tubes are inserted into the main veins
...
Oxygenated blood is pumped back into the aorta and then the heart
through another tube
...

o Example of this being in use: the heart and lungs must be temporarily
stopped during surgery for heart transplants and heart implants
...

● Identify the devices that constitute life supports systems in any major
hospital
...
3
...


● Discuss the terms ‘non-invasive’ and ‘minimally invasive’ in relation to
medical techniques
...

o Traditional surgery is invasive, requiring incisions or cuts to enter the
patient’s body
...

A small incision is made into the skin and specially designed surgical tools
are inserted through the incision to perform the required tasks
...

● Identify non-invasive diagnostic techniques including x-rays, ultrasound,
thermography, and magnetic resonance imaging (MRI) and discuss their
importance in diagnostic medicine
...
This property is
used in diagnostic medicine to get a clear picture of internal structures such
as the skeletal system and organ replacement without invasive, exploratory
surgery
...
The sound waves are transmitted
from a probe, penetrate the body and are reflected off internal structures
...
The echoes
are received and analyzed by the probe and converted into an image on the
screen
...
Tumors are more active metabolically and therefore
produce more heat
...

o Magnetic resonance imaging (MRI): also known as nuclear magnetic
resonance
...
The MRI machine produces a powerful magnetic field which causes
hydrogen atoms in water to line of parallel to the direction of the field
...
This change is
recorded and analysed
...

● Describe the advantages of using minimally invasive surgery techniques such
as keyhole surgery
...

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Senior Science Notes 2015

o Fewer side effects and less chance of complications that can occur as a result
of invasive surgery
...
This frees up
hospital beds and patients are back to work sooner
...


Information Systems:

9
...
1 – information systems are many and varied and depend on the
transfer of energy from place to place
...

o Message: Messages that have to be electronically transferred has to be coded
and may have to be re-coded in order to be transmitted via the carrier wave
...

o Transmission of coded messages: coded messages are sent on electric
currents or electromagnetic waves to the required destination
...
Second step is to convert
the code into a form that the receiver’s senses can detect and interpret
...

o Bar codes
o Body language
o Cable television
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Senior Science Notes 2015

o
o
o
o
o
o
o
o
o
o
o

CB radio
Compact disc
DVD (digital versatile discs)
Sonar
Facsimile
Film
Internet
International symbols
Telemetry
Touch, smell, taste
Sound

● Classify information systems as:
- Verbal and non-verbal
- Short distance and long distance
- Electronic and non-electronic
Verbal
● Talking
● Public address systems
● Mobile phones
● Cable tv
● Internet

Non-verbal
● body language
● radar
● sonar
● cable tv
● internet

Electronic
● public address systems
● mobile phones
● cable tv
● radar
● sonar
● internet

Non-electronic
● body language
● talking

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Senior Science Notes 2015

● telephone system
Short distance
● Mobile phone
● body language
● talking
● sonar
● mobile phone

Long distance
● cable
● radar
● internet
● mobile phone

● Recall phenomena and events where different forms of energy are used
...
Many phenomena are energy carriers (because they
have the capacity to cause changes when they encounter other objects)
...
Energy exists in many different forms, e
...

electromagnetic radiation, sound, thermal, electrical and potential
...
An electric current is the movement of electrons
through materials and, because of their nature and their movement, they are
energy carriers
...

○ Cathode rays (a continuous stream of electrons) have a number of
applications from the production of X-rays to the creation of images in
cathode ray tubes (CRTs) that are critical components of many television sets
and computer monitors
...

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Senior Science Notes 2015



o Land connected phones: Kinetic energy (sound)  electrical  kinetic
energy (sound)
...

o Radios: sound  electrical  radio waves  electrical  sound
...

Discuss the advantages of using a range of information systems
...

o They all have a specific application: e
...
FM radio waves are not destroyed by
natural phenomena etc
...


9
...
2 - Electromagnetic radiation can be modulated to carry different
types of information
...

o Infra red: Laser beams and thermal imaging
...

o Radio waves: AM radio (amplitude moderated), FM radio (frequency
moderated) and TV (used AM for picture and FM for sounds)
...

Types of waves
Advantages
Disadvantages
Microwaves (very short
Passes through the
Absorbed very easily by the
wave length radio waves)
ionosphere – making them
natural environment and
suitable for satellite to Earth man-made objects – e
...
rain,
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Senior Science Notes 2015

transmissions
...


concrete etc
...

Need special aerials to
receive them
...

existing technologies is
Can carry messages
limited – this causes lots of
instantaneously over a wide competition amongst
area
...

simpler than microwaves
...

it around corners and
Can be broadcasted to a
objects
...

areas means that a lot of
Frequency in transmission
energy is wasted – the
and reception of radio waves receiver must be tuned into
can be precisely controlled
...

 Identify communication technologies that use energies from the electromagnetic
spectrum for communication purposes
...

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Senior Science Notes 2015

Remote control
Satellite technologies

Mobile phone networks

TV broadcasting

Radio broadcasting

Allows external control of a
system – e
...
TV, video etc
...

Uses a combination of
systems from a range of
energy from the EM
spectrum
...

Radio is used for a broad
range of technologies
including AM and FM
broadcasting and amateur
radio
...


Short wave and long wave
radio waves – frequencies
ranging from 10 Mhz – 1
Mhz
...

Radio dial indicated
frequency range for AM: 540
– 1600 kilohertz
...
4
...

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Senior Science Notes 2015







Identify where information systems cannot physically link the information
that may be transmitted in a wave form through the atmosphere or space
...

o However, this is where EM waves come into play
...
The very high speed
of electromagnetic radiation (EMR) means that the time between sending,
receiving and decoding a signal is almost instantaneous for Earth-based
systems
...
This makes using them predictable
...
This effect is used by
shortwave AM radio frequencies
...

- Scattering occurs when shorter wavelengths strike an object
and are reflected in many directions, e
...
microwaves can be scattered by
rain
...

Describe the individual properties of visible light, radio waves (AM, FM and TV
waves) and microwaves and relate these to their use in communication
systems
...
4
...



Explain why an Earth-based satellite dish must always face the geostationary
satellite communicating with it
...
It
must be in an equatorial orbit
...
The
satellite dish must face the same direction at all times to ensure that signals
are received and retransmitted in the correct directions to the intended
receivers
...

o In order for a satellite to remain in orbit over the same point on the Earth’s
surface at all times, it must be located 36 000 kilometres above the equator
...

o The Earth’s gravitational pull keeps the satellite in orbit
...
Although they are
pulled towards the Earth by gravity, their speed enables them to
keep falling over the horizon
...

Tracking stations on Earth use radio signals to activate small rockets on the
satellite to keep them in the correct orbit
...
4
...



Identify communication technologies that transform one type of energy into
electrical energy
...

o Essential parts of scanning digital technologies are:
o A transmitting device: this device translates visual matter (text and graphic)
of the copy into electrical impulses according to a set pattern
...

o Digital technologies:
o Uses a process called digitization (involves converting sound or light into
computer language [a code], transmitting it and converting it back to its
original form at the receiving end)  to input information into a computer, a
keyboard, light pen, scanner, mouse, floppy disc, CD or drawing pad is used
...

o Output from the computer is via the screen, print or modem (fax, telephone,
and internet)  they could also provide input
...

o Light energy  electrical energy  light energy
o In a typical system, the scanner consists of a source projecting a narrow
beam of light and a photoelectric cell
...

- The output of the photoelectric cell is suitably amplified in a
coupling device and used to modulate a carrier radio signal, or is transmitted
directly over the telephone cables
...

o In an analogue system – information is transmitted in the form of a wave
...

Explain how the coding of the image into a series of zeros and ones allow its
transmission and ultimate decoding
...
e
...
Each dot is either on or off, depending on whether it is black or
white
...

o In this way, the device translates a picture into a series of zeros and ones
(called a bit map) that can be transmitted like normal computer data
...

o Steps to calculate binary codes:
- Divide number by 2 and write down any remainders
...

o For example:
373
186

0

93

1

46

0

23

1

11

1

5

1

2

0

1

1

0
o

1

0

In the table above: 373 ÷ 2 = 186
...
However when we change to binary digits,
we take 186 and write the decimal part as a remainder – 1
...

o Hence, we slowly start to develop the binary code for the number 373
...

o Analog to digital:
Requires a coder and a decoder
...
This digital electrical
impulse is then transferred to a light source via copper wiring
...

Repeater: retransmits the signal (digital light impulses) at a higher level or
power or onto the other side of a obstruction so the signal can travel longer
distances  digital light impulse transmitted to a light detector in optical
fibre
...

Decoder: transforms digital electrical impulses back into analog electrical
impulses and that can be picked up and used by phones, wifi modems, fax
machines etc
...

Copper cables requires repeaters to boost
signals every 1
...
4
...



Outline properties of optical fibres as communication carriers
...
This is achieved by covering the glass with a cladding of
denser glass or plastic
...
This process is known as total internal reflection
...

 Outline the differences and the relative merits in the use of fibre optic cables
and metal cables to transmit and receive information
o Total internal reflection occurs when light travelling from a more-dense to a
less-dense medium hits the boundary between them
...
When the angle of incidence is greater than the
critical angle, total internal reflection occurs, i
...
all the light is internally
reflected
...
g
...

radio waves
...

static
...

replaced often
...
Thicker and heavier (in regards to metal
cables)

Option module: Disasters
9
...
1 – Disasters may be natural or caused by human activity
...

o Disasters are known to be unfortunate, and often, sudden events that result
in large scale structural and environmental destruction as well as loss of life
...

Chaotic and destructive in nature
...

Involves the damage leading to large costs in repair and/or
replacements
...

-



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Senior Science Notes 2015



Identify a range of disasters associated with human activity using specific
Australian examples
...

o A dust storm in Melbourne (1983) resulted from a change in conditions
...
After a dry
period, a freak storm built up which carried millions of tonnes of topsoil off
the farms into the centre of Melbourne
...
At the
same time, the farms lost their topsoil that is essential to provide nutrients
for crops to grow
...
Although it
could be called a natural disaster human error certainly contributed to it
...
In the race of 1998, everything went well until the second night,
when strong winds swept up from Bass Strait, producing huge seas
...
A race that is well organised, with participants who are well
prepared for typical storms, turned into a disaster due to rapidly changing
weather conditions that were not passed on to participants in time
...
For example it is now accepted that
a contributing factor to the damage caused during Cyclone Tracey was the
design of the houses in Darwin
...

o In cities, flooding can occur if the drainage systems built by people cannot
cope with the storm water
...


9
...
2 – Technological developments have improved our ability to
monitor and predict weather patterns
...

o Atmospheric pressure: force per unit area due to the weight of the
atmosphere  measured in hectoPascals ( 1 hectoPascal = 100 Pascals)
...

Identify the distance between isobars on a weather map indicates the relative
amount of atmospheric pressure in an area
...

o If isobars are further away from each other  differences in air pressure
between two places isn’t very large
...

o Cyclones + tornadoes: both very violent storms caused by large differences in
air pressure
...

Describe technological advances that have contributed to increased
understanding of meteorology
...

o Technological advances include: datalogging equipment allows unstaffed
stations to carry out measurements at regular intervals 24 hrs/day  data
can be retrieve when needed  allows ‘weather stations’ to be placed in the
most inhospitable places; measuring equipment has become more reliable
and accurate due to different sensors that can be connected to datalogging
machines
...

Describe the relationship between the monitoring of weather patterns by
radar and laser light and the analysis of reflected wave patterns by computers
...
g
...

o Radar excels at piercing bad weather  however needs snow, raindrops or
hail to get a signal  e
...
LIDAR struggles to go through thick clouds and
heavy rain
...

Explain why satellite photographs of cloud patterns have improved the
reliability of interpretations of weather regularities and knowledge of global
weather patterns
...

o E
...
MTSAT – 1R: Japanese build satellite is snapping hourly photographs of
weather fronts in the Asia – Pacific region and is beaming them down to a
base station at Cribb Point, Victoria
...
5
...







Outline differences in P, S and L energy waves produced by an earthquake
...

o S (Secondary waves): transverse waves; travel slower than P waves and the
differences between the arrival of P and S waves can be used to determine
the epicenter of the earthquake
...

Identify energy transfers and transformations involved in L waves as they
travel along the earth’s crust
...

o As L waves travel along the surface of the earth, they move the ground from
side to side  buildings standing on the ground need to have the strength or
flexibility to cope with the movements of L waves
...

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Senior Science Notes 2015



o Richter Scale: A formula based on amplitude of the largest wave recorded on
a specific type of seismometer and the distance between the seismometer
and the earthquake  invented in 1930s by Charles F
...

o Mercalli Scale: This scale measures the intensity of an Earthquake by how
much damage has been caused  intensity ranges from 1 – 10, with 1 being
extremely weak/no effect and 10 being extreme/damages + lives lost
...


Figure 1 - Taken from HSC Online
...

o Earthquakes usually happen deep underground and can rarely be monitored
or predicted until an extreme one occurs
...

o In order to predict where an earthquake may strike, people monitor all the
parts of the Earth that are on Plate Margins
...

o Some of the conditions in Australia that contribute to triggering a bushfire
include:
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Senior Science Notes 2015

Periods of hot, dry weather that can leave plants dead and dry  excellent
fuel
...
g
...

Hot weather + strong winds = fire starter  strong winds provide a great
oxygen supply to already lit fires and can carry sparks to other places
...
g
...

Many of our native trees and shrubs contain chemicals that are flammable 
e
...
eucalyptus leaves have oil in them
...

Describe the effect of the slope of the land and intensity of the wind on the
speed of the bushfire
...

Blows fire across the landscape
...

Hot air rises so that the heat from a fire at the foot of a gorge will rise and dry
out vegetation higher up, probably igniting it
...

As a result, hilly/mountainous land and wind can make fire spread rapid and
change directions suddenly  this is dangerous because it can trap people
who aren’t ready to brace the incoming fire
...

o When a bushfire rages, it generates a huge amount of heat
...
As a result of this rising air, a
large convection current is produced, which is noticed as a very strong wind,
in front of the fire, blowing back towards the fire
...

o Controlled burn: the fire is lit and watched carefully as it burns  kept quite
small so it does generate enough heat to do major damage to other plant life
 the job of the fire is to burn up all plant material which may pose a risk in
summer
...

Is lit in an area where natural growth has produced plant material which may
pose as a risk in hot weather
...
This fire is meant to
use up fuel as the major fire approaches the back burn must be lit far
enough away so that it has enough time to burn up the fuel but not so far that
it can get away
...

Is lit to make sure the bushfire runs out of fuel faster
...


9
...
4 – Warning devices can also be used to detect disasters associated
with human activity
...
The radiation is detected and monitored  however if there is
smoke in the room, it inhibits the radiation’s ability to penetrate the air by
entering the space in the detector  this change causes the alarm to go off
...

o Sprinkler system: heat causes the seal within the sprinkler system to melt,
releasing water through the system in a burning building
...
5
...





Identify the role and account for the need of coordinated help services in
times of potential disasters including:
Police
Fire brigade
Ambulance
State Emergency Service
Rural Fire Service
Community organizations
o Police: ensures that peace and order are maintained during a disaster 
includes crowd control (keeping onlookers away, keeping traffic flow around
the disaster)  often will be called on to provide evidence in cases where an
inquiry into the cause of a disaster is needed
...

o Ambulance: trained to provide First Aid and emergency treatment  ensures
victims of accidents or disasters are given treatment to ensure survival or to
stabilize their condition so they can be transported to hospital to receive
further treatment
...

o RFS: staffed by volunteers who give up their spare time to be trained in fire
fighting and rescue techniques  extremely important in fighting bushfires
since they may be the only people around who knows how to
...

Assess impacts of technological developments on the warning that can be
provided about impending disasters
...

Improved communications networks using satellite systems, radio and
telephone to detect and warn people of changing conditions
...

These early warnings rely on availability of broadcasting techniques such as
radio and television

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