Chemistry Research Assignment Part A – The Production of Materials:
1. Use available evidence to gather and present data from secondary sources and analyse progress in the recent development and use of a named biopolymer. This analysis should name the specific enzyme(s) used or organism used to synthesise the material and an evaluation of the use or potential use of the polymer produced related to its properties.
a) Name a biopolymer (eg. Biopol) outlining how it’s produced.
Biopol: Made in the 1960s In an American company. This biopolymer is a PHA and is produced industrially by growing it in tanks with bacteria such as Alcaligenes eutrophus along with a carbon based food source. It is then isolated from the tank to be purified by various methods such as dissolving the PHB in trichloromethane and then removing all its waste to create Biopol.
b) Construct a table, relating its uses/possible uses to its properties.
Uses Properties related
Act as a carrier for slowly releasing insecticides and herbicides and fertilizers Biodegradable – able to break down in the natural environment
Use as containers for plastics as well as shampoo containers and cosmetics insoluble in water and relatively high tensile strength
Medical applications Biocompatibility and biodegradable
Non toxic

c) Evaluate the importance of this biopolymer now and its potential for use in the future based on part b.
Biopol is quite an important biopolymer as a future resource because firstly, there have been attempt to make this product more economically by genetic engineering. It’s most important expansion would be in the medical field due to the fact that it is a non-toxic, biodegradable and biocompatible polymer. If this polymer can be produced more efficiently there may be increase use of Biopol in normal disposable products like nappies and utensils.

2. Process information from secondary sources to summarise the process involved in the industrial production of ethanol from sugar cane.
Construct a Flow Chart outlining how ethanol is produced from sugar cane in an industrial setting.

3. Process information from secondary sources to summarise the use of ethanol as an alternative car fuel, evaluating the success of current usage.
Assess the potential of ethanol as an alternative fuel and discuss the advantages and disadvantages of its use.
Ethanol has been proposed as an alternative to petroleum. This varies from adding it to petrol for use in current engines to redesigning the car engines to run totally on 100% ethanol.

a) Describe the various ways in which ethanol can be used as an alternative to petrol. Include the % of ethanol used in the replacement product.
For the past decade or so, as the world’s oil and other fossil fuel reserves slowly deplete, there has been a growing interest in search for a future alternative fuel. For some time already, Ethanol (C2H5OH) has always been seen with having great potential as an alternative future fuel to replace petrol. With the world’s continual growing appetite for fuel resources, experts estimated that the world’s fossil fuels resources will eventually run out; indicating the urgent need for an alternative fuel. Because Ethanol is a renewable resource and can be extracted from natural, renewable materials such as wheat, barley and sugar cane by fermentation, Ethanol is a promising option.
In Brazil, however, ethanol has been used as their primary fuel source for over 30 years already. Motor vehicles can either run on 100% pure ethanol as an automotive or be blended with other fuels; such as petrol and even diesel, in a range of different percentage compositions. However, if the percentage of ethanol exceeds a certain limit, normal cars would not be able to run and a redesign of the engine is required.
The following highlights some of the most common blends and their percentage replacement levels:
• Gasohol – 90% petrol and 10% ethanol (E10) - (sometimes methanol is used but it is toxic)
• E85 – 85% is ethanol – increasing usage of E85 in the United States. This requires special engine modifications using Flexible Fuel Technology.
• E22 – 20-24% is ethanol – a common blend present in Brazil where the motor engine requires various specific modifications to run on E22.
• E100 – 100% pure ethanol – Used in Brazil where the engine is specifically optimised to run on E100.
Currently in Australia, some of our petrol is blended with ethanol but only around the 10% mark. There are some developing projects to extend to 20% ethanol fuels.

b) What happens to car emissions when ethanol is blended with petroleum?
By adding ethanol to petroleum, notable changes in the car’s emissions include reduced emissions of:
• Carbon Monoxide,
• particulate matter (such as dust, carbon soot and other solid pollutants),
• hydrocarbons and
• carcinogens (cancer causing pollutants)
Because Ethanol is classified as an oxygenate fuel; a form of additive with hydrogen, oxygen and carbon present in its molecular structure, it adds extra octane to the fuel, allowing longer usage but also helps in complete combustion. Instead of emitting pollutants such as Carbon Monoxide; due to incomplete combustion, the extra oxygen molecule helps to make complete combustion of the fuels.
On a negative note, by blending petrol with ethanol, sometimes incomplete combustion of alcohols occurs in cars and would release toxic pollutants such as ethanal (acetaldehyde). This issue supports the idea of using only pure ethanol fuel, rather than as blended fuels.

c. What are the advantages of using ethanol instead of petrol or as an additive to petrol?
d. What are the disadvantages of using ethanol instead of petrol as an additive to petrol?

In certain aspects, ethanol does show considerable potential as an alternative replacement fuel compared to petrol. Let us compare some of the properties/features of ethanol with petrol as fuels. All figures are only approximates.
Properties/Features Ethanol Petrol
Energy per gram 30 kilojoules 48 kilojoules
% of Carbon 50-53% 85-87%
% of Hydrogen 11-13% 14%
Flashpoint 14 degrees Celsius -43 degrees Celsius
Vapour pressure above the liquid 16kPa 76kPa
Density 0.79g/ml 0.74g/ml
Note: (The table of data above was obtained from a teacher’s handout booklet ‘2 Unit Chemistry HSC Course 05/06 Production of Materials Module 9.2 – Work booklet notes and questions page 5.31’.)

In terms of environmental and safety concerns, this table indicates that ethanol is more preferable to use as a fuel instead of petrol. The advantages and disadvantages of using ethanol instead of petrol or as an additive to petrol is listed below:

Advantages of Using Ethanol:
• A renewable resource. Able to be extracted from renewable, naturally occurring materials. (e.g. sugar cane)
• A cleaner burner – reduces the amount of emitted pollutants and greenhouse gases. (Global Warming)
• Relatively safer for use – less volatile, less pressurised and has a higher flash point .Hence less explosive.
• Does not leave residues in the storage container or pipes whereas petrol does.
• Production/Refinement of petrol is rather complicated. Ethanol may be a bit easier to manufacture.
• Petrol engines release too much heat. Requires lots of cooling systems.
• Ethanol has a higher octane percentage rate. Can be blended with the petrol and limits the use of dangerous additives like tetraethyl lead and benzene-based chemicals.
• Ethanol is able to biodegrade. If accidental spills happen, it could slowly disappear or even be diluted to reduce its concentration.

Disadvantages of Using Ethanol:
• Large areas of land needed to be used for growing crops; the raw material needed to make ethanol. Raises all sorts of environmental impacts – deforestation, salinity, soil (land) degradation and erosion.
• If blended with petrol, the ethanol becomes a solvent and would release chemical sludge. This clogs up the cars engine and fuel pipes. Suggests a need for just pure ethanol fuel.
• May sometimes have incomplete combustion of ethanol. This would release dangerous chemicals like ethanal, causing health issues like triggering asthma attacks.
• In some cases, accidental spills may still be hard to control or recover from; especially in lakes, oceans etc.
• A great deal of wear would be inflicted on the car engine as the fuel is not oily as like before.
• Water must be removed from the ethanol to avoid problems such as corrosion of engine parts.

e) Evaluate how successful the campaign to replace petrol completely or partially as a blended has been.
f) What is the potential for ethanol use in cars in the future? How likely is it to be used in each case?

The use of ethanol as an alternative fuel has been practiced in Brazil for over 30 something years and clearly shows it to be a highly successful campaign. In the past, Brazil was a country containing very few resources of hydrocarbons; with constant spasmodic fluctuations in their economy. Consequently, Brazil would have to need to import oil and other fuels to sustain the countries needs. In addition, the 19973 Oil Crisis forced many countries to take decisive measures. So in the mid 1930’s the Brazilian Government entered an entire new industry of fuel; abandoning the great reliance of fossil fuels and using their sugar cane plantations to produce ethanol as their alternative fuel.
This act by the Brazilian Government to subsidise the production of ethanol from sugar canes is to reduce the amount of oil imports from countries, be able to increase the employment rate of its people and strengthen its economy by importing their product. By using ethanol, Brazil is able to cut back the costs of importing oil from other countries, survive the Oil Crisis and be able to use their sugar cane crops and plantations to manufacture ethanol. By doing so, Brazil is also able to participate in global trades; importing gallons of their ethanol to other needing countries such as America and also recently, Japan.
At first, this project was highly expensive for the government to subsidise and was seen as an unpractical proposition. But today, Brazil now stands as the world’s largest producers of ethanol from sugar cane crops and import millions of gallons to many huge nations and countries.
Switching to ethanol as an alternative fuel provided many advantages and positive impacts on the environment and economy as a whole. Because ethanol is a renewable resource, being able to be manufactured from natural raw materials in plants, there is no fear of depleting the resource in the same way we are doing to our fossil fuels. In environmental aspects, it releases less pollutants and greenhouse gases, which is a positive impact for the world, considering all the issues arising from global warming today. Also, Brazil has a lot of land which is used fro growing sugar cane and so, it is more economically viable to use these naturally, renewable resources to produce ethanol. There was also no more need to depend on Middle Eastern countries for importing oil and fuel.
Since then, Brazil has been using ethanol as fuel for cars with an approximation of 20% of its population using pure ethanol fuel for their cars. When American countries also started to exploit on this industry, they began to construct dozens of distilling plantations across the country; to manufacture and refine the ethanol from sugar cane. Now, most of the American nations use half-blended petrol and ethanol as car fuel. It is less pollutant and has a greater petrol life than just ordinary petrol; ethanol contains more octanes as well.
However, the process was costly, since huge amounts of energy were needed to separate the ethanol from the aqueous ethanol during the fermentation process. But yet, when comparing these costs with the money they earn from importations, it is still a profitable business.
However the success of the campaign in Brazil does not reflect upon Australia. Scientists and other oil experts are in discussion over this project and whether it will be a possible project over here in Australia. Our fossil fuel reserves are rapidly depleting and an alternative fuel is required. The project is not economically viable; as full importing from Brazil would be too costly. There would be rise in oil prices on different types of fuels.
On a second option, we could choose to manufacture ethanol using sugar canes here in our country sides.
In regards to this, experts predict that even if the whole of the Australian sugar cane industry was used for manufacturing ethanol, the production rate would not be sufficient to satisfy the usage of fuel for our Australian cars.
Recently, however, in an interview with two Australian scientists, Dr. Paul Attfield and Dr. Philip Bell, there seems that there may be a possible solution to this problem. In an experiment, the two scientists “actually managed to unlock more sugar within sugarcane almost doubling the ethanol yield” (quote from interview at http://www.abc.net.au/catalyst/stories/s1763365.htm). By using genetically modified yeast, it would extract double the amount of sugar from sugar cane.
This may be the start of a possible future use of ethanol as fuel, but currently, the plans are still unclear.
Even if manufacturing of ethanol can be economically done, all of our cars would be remodified to suit the new fuel.
Australia does use fuel with blends of ethanol of 10-20% in it, but car engines would need to be redesigned to use E22. There is a major concern of sales of 20% ethanol blend with 80% petrol. The Australian Government would wish to restrict this down to 10% as there is concern that having too much ethanol in fuel may require entire engine modifications. The likeness of using 100% ethanol is small, as engine would need to be redesigned and cost a lot of money. Uses in petrol blends are more likely in Australia but would still remain at low ethanol percentages.
Scientists may have discovered ways to acquire more sugar from sugar canes and other crops to increase the production of alcohol (using non-genetically modified yeast), but at present the issue is still uncertain in terms of its viability.
Brazil is a definitely an indication of a possible future expansion; that ethanol does hold the potential as a future alternative fuel but due to the fact that our car engines would all need to be redesigned and other factors, it is at present, no economically viable.

4. Gather and present information on the structure and chemistry of a dry cell or lead acid cell and evaluate it in comparison to one of the following:
• Button cell
• Fuel cell
• Vanadium redox cell
• Lithium cell
• Liquid junction photovoltaic device (eg the Gratzel cell)
In terms of:
• Chemistry
• Cost and practicability
• Impact on society
• Environmental impact

a) Choose ONE dry cell or lead acid cell. Describe how this battery works. Include diagrams.
Leclanche Dry Cell:
Since its development in 1866 by French engineer Mr. Georges Leclanche, the Leclanche Dry Cell is one of the most commonly used galvanic cells today; used in a wide range of everyday applications with very little modifications since then. The dry cell, as suggested by its name, contains no liquid-chemical electrolytes but instead is an aqueous chemical paste. It is categorized as a Primary Cell due to the fact that after the battery life has been used up and discharged; it cannot be recharged and used again and hence must be disposed of. One of the most common Leclanche dry cells is the carbon-zinc battery. The cell diagram of this battery is: Zn | (ZnCl2), NH4Cl| MnO2, C
A diagram of this battery and its structure is illustrated below:

Image source: http://en.wikipedia.org/wiki/Image:Zincbattery.png
As show above, the battery is composed of an outer casing of zinc which is the anode (-) electrode. In the centre of the battery, a graphite rod (carbon) is the cathode electrode with an aqueous paste of ammonium chloride (electrolyte), manganese dioxide and zinc chloride. When the cell is used, the zinc ions begin to form and help to discharge the ammonium ions. At anode, oxidation takes place here with the loss of electrons and the zinc would gradually dissolve into nothing. This anode reaction can be expressed as: Zn(s)  Zn2+(aq) + 2e-
The cathode reaction can be represented as: 2MnO2(s) + 2H(aq) + 2e-  Mn2O3(s) + H2O(l)
As shown in the cathode reaction, Manganese Is reduced from an oxidation state from +4 to +3 during the electron transfers and now, the Manganese dioxide would contain the electrolytes of the cell; ammonium chloride and zinc chloride. In addition, Ammonium ions can also give the hydrogen ions which are needed for the reaction in the cathode terminal to occur.
b) Choose ONE button cell, fuel cell, vanadium redox cell, lithium cell, liquid junction photovoltaic device (eg the Gratzel Cell) Describe how this batter works. Include diagrams.
Lithium Cell:
The Lithium cell is a primary battery that contains lithium as its anode. Lithium is an electropositive element, being at the top in the table of redox and longs to form positive ions and oxidise. As shown in the diagram, the lithium battery is made up of a carbon negative electrode and a lithium positive electrode. As the battery charges, the Lithium ions are transported to the negative electrode and reverses when not in use.
One of the main families of the lithium cell is the lithium-thionyl chloride cell. This particular cell uses thionyl chloride as its cathode the chemical lithium tetrachloroaluminate as its electrolyte. A cathode current collector made up of porous carbon m aterials serves to collect electrons from the outside of the circuit.

c) Compare your battery from part a to that in part b in terms of:
I) How it generates electricity and the chemical reactions involved:

The chemical reactions of the Leclanche dry cell and the Lithium cell has already been demonstrated above. In the dry cell, the anode reaction can be expressed as: Zn(s)  Zn2+(aq) + 2e-
The cathode reaction can be represented as: 2MnO2(s) + 2H(aq) + 2e-  Mn2O3(s) + H2O(l)
It was considered a major advancement of the Danielli cell as it does not contain liquids anymore but more of a damp paste. The dry cell uses an electrolyte paste in the basic galvanic cell principal whereas the lithium cell can have a combination of lithium with other oxidisers to produce maximum electricity. The dry cell uses the basic electrolyte with two electrodes and has the cycling transfer of electrons, producing currents up to 1.5V. The lithium cell is mainly focused on combining with a number of cathode materials such as iodine solid, manganese dioxide solid. If combined with an oxidizing agent, down at the bottom for the redox table, it would generate huge amounts of electricity up to 5V.
So in general, the dry cell deals with the basic oxidation/reduction reactions whereas the lithium cell would form positive ions and oxidise to create electricity.

II) Cost of production, average battery life and ease of use:
The Lithium cell aims to achieve high voltage that can power appliance for a long time. Lithium dry cells are generally long lasting compared to the dry cell where it would easily discharge and have to be discarded. However, lithium cells contain a degree of danger as it would explode if the two parts of the battery come into the contact. Water can also trigger this if it touches with the lithium. Dry cells are relatively low costing and can be made from natural materials. Leclanche cells are basically the basic battery one would use everyday for normal applications whereas the lithium cells would be used in applications which need to be used over a long period of time.
Both are relatively practicable in use but the lithium cell has a definite longer life than the dry cell.

III) Types of devices that use that battery and how the development of this battery has allowed the development of new technologies changing the world we live in.
As mentioned before, dry cell has undergone little modifications since its development in 1866 and can be used in almost everyday applications that require a simple battery to run. Dry cells, such as the Everyday AA 1.5V battery help in the development of making other forms of technology because the dry cell can be developed into a portable source of energy. This allowed usage in all equipment that is small and able to be carried around such as torches, many toys, transistors, games and other sors of electronic devices.
The Lithium cell had a great change in more serious situations. Because of its long life, Lithium cells are mostly used in areas were continual usage is needed, such as the continual monitoring in military camps. Also, by developing these batteries with a greater voltage, stronger devices and technologies could be made and allow a greater potential use.
IV) How the batteries are disposed of and the dangers they pose to the environment.
One of the most notable problems was at the Homebush site where batteries were dumped into a mangrove swamp land; causing millions of dollars to clean up. The dry cell is generally a much safer battery for the environment compared to other batteries but correct disposal must still be followed. In the Homebush site, cancerous tars and other organic-chloride waste problems had leaked into the water right into Sydney Harbour. However, the chemicals are able to be recycled and are less toxic than other chemicals. The lithium cells are more dangerous due to the reactivity of lithium metal. If could cause explosions and start fires if incorrectly disposed of. Like all batteries, correct management should be taken as the chemicals would all damage the environment to an extent. However, in this case, the lithium cell would still be a much more dangerous cell than the dry Leclanche cell.
Evaluate which battery:
i)Produces the highest voltage:
The lithium cell is definitely the battery that produces the highest voltage due to the reactivity of the metal lithium. It can reach a voltage of almost 5V whereas the dry cell is only at a minimal of 1.5V. ii) Is best value for money: This is dependent on the type of use you need. If everyday applications such as battery for a torch, the dry cell is the one to buy. Generally, the making of the dry cell is relatively cheaper than that of the lithium cell due to their different chemistries and uses. The lithium cell is more expensive as it can produce more voltage and be used for a long time. However, the situation of the two batteries are not the same. iii) Is most convenient to use:
The Leclanche dry cell is definitely the most convenient to use. It is small, portable and able to be fitted to almost any application. The lithium cell is dangerous to carry around and is not much used nowadays. iv) Has had the greatest impact on the society in the past:
The dry cell has had the greatest impact on society in the past. These were one of the first portable and efficient types of batteries invented and we continue to use this today. There is also the Homebush incident which raised a lot of concern and awareness for the correct disposal of batteries.
v) has the greatest potential for the future:
The lithium cell, being a rather reactive metal would find great use in the future. The dry cell is more of a minor battery used for every applications and soon may be outdated. The lithium cell may continue to serve for the future in more important uses. vi) Poses the least risk to the environment: The dry cell is the safest and poses the least risk. This is because of the chemical that make of this battery. Apparently, lithium is a rather dangerous metal and is not safe for it o be drifting in the environment. It is quite toxic and dangerous.
5. Process information secondary sources to describe recent discoveries of elements.
a) Construct a table of the last ten discovered elements and date in order of most recent to oldest.
Date discovered Element number Name of Element Discoverer/Place of Discovery
2006 118 Ununoctium Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory
2004 115 Ununpentium Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory

2004 113 Ununtrium Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory

2001 116 Ununhexium Joint Institute for Nuclear Research in Dubna 1999 114 Ununquadium Joint Institute for Nuclear Research in Dubna

1996 112 Ununbium S. Hofmann, V. Ninov et al, GSI
1994 111 Roentgenium S. Hofmann, V. Ninov et al, GSI
1994 110 Darmstadtium S. Hofmann, V. Ninov et al, GSI
1984 108 Hassium Peter Armbruster and Gottfried Münzenberg,
1982 109 Meitnerium Peter Armbruster and Gottfried Münzenberg, GSI
Note :( All data was obtained from http://en.wikipedia.org/wiki/Discovery_of_the_chemical_elements#21st_century)

c) There is a similarity between how the most recent elements are now discovered. Describe how we discover new elements today.
As shown in the table above, the most recent elements discovered by scientists in the past few years mainly consist of transuranic elements (E.g. elements with their atomic number after 85). For these transuranic elements to be artificially synthesised, certain particles are required to be accelerated at high frequencies and bombarded onto the elements. For such as case to progress, high speed accelerators are required.
Today, all the newly discovered elements are synthesised in 3 different types of high speed accelerators: synchrotrons, linear accelerators and cyclotrons.
Linear accelerators, as suggested by its name, are relatively long pieces of apparatus that accelerates high –energy electrons for radiotherapy and other studies of physics. Synchrotrons are used for accelerating protons close enough to the speed of light. Cyclotrons, on the other hand, accelerate particles in the shape of a spiral as shown in the diagrams below:

Image Source: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/cyclot.html

In this process, a new radioisotope can be created by bombarding charged particles (usually the nuclei of elements such as Hydrogen, Helium and Lithium) at the nucleus. However, for the charged particles to be able to penetrate through the nucleus, they need to acquire enough velocity to withstand the great repulsive forces of caused by their electrostatic forces.
The particle accelerator uses electrical and magnetic fields to acquire great velocities by alternating them to bend the paths of the charged particle into the spiral pathway. As the cyclotron continues to accelerate the charged particle, it would continue its uniform circular motion until it reaches the gap. When passing through this gap, the electric field accelerates it to a higher velocity. The particle would then start to trace a bigger arc and each time it passes the gap, it would gain extra velocity and eventually it would attain enough speed to travel in the large arc and hit the targeted nucleus at the exit.
Because these elements are synthesised by nuclear transmutation, namely fission and fusion, the bombardment of charged particles can cause a stable new element or produce an unstable nuclei that would become a radioisotope undergoing radioactive decay.
Neutron bombardment however, does not require high speed accelerators as they are neutral in charge do not experience any electrostatic forces Neutrons are easily absorbed to form new elements when undergoing a reaction in a nuclear fission reactor.

6. Identify one use of a named radioisotope:
­ in industry
­ in medicine
Describe the way in which the above named industrial and medical radioisotopes are used ane explaining their use in terms of their chemical properties.
a) Choose one isotope that is used in Industry and describe how it is used. Explain how its properties (especially half life) make it a good choice for this use.
Industry – Cobalt-60:
Cobalt-60 is a widely used radioisotope in the field of industry. It is synthesised by neutron bombardment on the stable isotope of Cobalt. In industry applications, Cobalt-60 is used for industrial radiography. That is, inspecting and examining the conditions of gas and oil pipelines, jet turbine engines, metal welds and castings in airplanes, walls and metal machinery for cracks and defects.
A beam of radiation from a source is directed at desired structure. On the other side, sheets of radiographic film are placed. If cracks or any signs of wear are present, then it would be exposed onto the film and would clearly show the area of defect. This is an extremely important application as many of these constructions could slowly deteriorate and wear away; causing danger to people and the environment. Cobalt-60 is most suited and preferable in these applications, mainly due to its penetrative power and half life.
• Cobalt-60 is a gamma emitting radioisotope; releasing highly penetrative radiation able to penetrate through materials (including metals) up to about 20cm thick. The penetrative power of Cobalt-60 allows it to penetrate through almost everything which is useful during inspection and efficient in detecting damage.
• The half-life of Cobalt-60 is also another useful property for these industrial applications. Having a half-life of about 5.27 years, Cobalt-60 is able to stay around for a long time. Hence, a single source of Cobalt-60 can be used for a long time without any replacements or maintenance. It would allow continual scanning of objects.
However because of its dangerous penetrative ability, it is chemically stored as a source in a sealed container and would remain chemically inert while undergoing radioactive decay. The container is used to protect the user from radiation exposure.

b) Choose one isotope that is used in Medicine and describe how it is used. Explain how its properties (especially half life) make it a good choice for this use.
Medicine - Technetium-99m:
Technetium-99m is one of the most extensively used radioisotopes in medicine, ranging in a variety of applications; detecting symptoms of abnormities, monitoring bodily functions and blood flows, diagnosis and treatment of diseases, various organ imaging and finding cancerous cells.
Technetium-99m is artificially made in nuclear reactors by bombarding Molybdenum 98 with neutrons (fission reaction). This results in Molybdenum-99 being produced plus a gamma ray. By using the long half life of Molybdenum-99, more Technetium-99m can be created from its ‘parent isotope’.
• Technetium-99m is an excellent radioisotope to be used in nuclear medicine due to its many useful properties. Technetium-99m has a very shot half life, approximately 6.01 hours. Because of its low half life, it can be put into the body for medical investigations without fearing it would stay in the body too long to damage it. It provides enough time for doctors to examine and treat the patient while not exposing the patient too long with radiation.
• This radioisotope also emits very low energy gamma radiation, which also greatly minimises any possible damage that might be dealt to the bodies tissues. However, this radiation can be picked up by sensitive gamma ray detectors to accurately pinpoint the cancer.
• It is also a very light isotope. Therefore, its decayed products would not be radioactive and harm the body.
• Technetium-99m can also be very easily excreted from the body (reduces amount of exposure).
• Technetium-99m is a transition metal. Because of this, technetium-99m has many valencies to bond with a wide range of compounds and biological carriers; allowing it to be transported to various organs and tissues without problem. For example: Technetium-99m can be linked with some blood serum and then injected into the bloodstream to detect and blood clots or circulation problems. Or Technetium-99m can be linked with some dimercapto succinic acid and then injected into the patient to scan images of the kidney.

7. Use available evidence to analyse befit s and problem associated with the use of radioactive isotopes in identified industries and medicine:
a) Choose an industry that uses radioisotopes: Industrial Radiography for Manufacture of metal
b)
Radioactive Isotope Main use
Iridium-129 Placed in gauges to monitor metal sheets, textiles and other paper and photographic film. A beam of radiation is directed at the sheets in this industry to control the thickness of the products. The amount of radiation passing through the sheets shows the thickness of the metal sheets and hence can be modified to suit the purpose.
Radioactive Isotopes can penetrate the sheet based on its thickness and also density. So by using radioisotopes, the correct dimensions can be made and produced.
Cobalt-60
Caesium-137
Ferium-55
Nickel-63

c) How do they benefit from using radioisotopes?
The main benefits of using radioisotopes are that it is much quicker and efficient to produce the metals. This radiographing uses ionizing electromagnetic radiation to see through things which we cannot. By using this, workers would not need to manually test the metal sheets and have a fast production of materials. Most of these radioisotopes have a high penetrative power and is able to penetrate metal materia up to 20cm long. This allows the operators to precisely measure and cut the dimensions to fit the purpose. The use of these radioisotopes can also help detect any defects in the products. It can check on the condition of the sheets and allow the manufactures to fix any problems.
d) What special precautions do they take and what are the dangers associated with using radioisotopes?
Radioisotopes are unstable and constantly undergo radioactive decay, emitting large quantities of radiation. Prolonged exposure to radiation results in tissue damage as well cancer growths and poisoning. Therefore when handling radioisotopes, special care is needed.
Because most of these are high emitting gamma radiation sources, a lot of precaution is needed. Firstly, the source is placed in a sealed container to prevent being exposed to the user and damage his tissues. The source should be handled with gloves and other protective clothing. In case of leaks, special devices should be installed to monitor the emissions and respond if the emissions pose any danger.
e) It is said of radioisotopes that the same thing that makes them useful makes them dangerous. Discuss this in terms of parts b; c and d.
This statement is correct. In industrial radiography, high penetrative gamma emitters such as Cobalt-60 are used of. Being able to penetrate through metal and everything else it is a dangerous source to humans. However, it is exactly valued for this penetrative power that it is used in this industry and so special precautions are needed. Cobalt-60 has a long half life would cause damage to your body if exposed but it is this half life that makes the metal sheet fabrication easy to monitor and modify. It can continually help the operator scan the sheets before having to be measured and cut up. In all applications of radioisotopes like medicine and the industrial field, there is always a threat and danger posed against the people. Radioisotopes are valued for their properties, being able to see through material and kill cancer. But this power is dangerous and could kill us if exposed too long so caution is needed when handling these. Radioisotopes are useful resources to help monitor safety, treat cancer and ring smoke alarms but its usefulness is also a danger for its users
f) Construct a table outlining how the common radioactive isotopes are used in medicine.
Name of Element Main Uses
Calcium-47 Use to study and diagnose diseases of the cells, bones and other calcium metabolic diseases
Caesium-137 Diagnosis of cancer in radiography
Cobalt-60 Killing of cancer cells and sterilizing medical equipment due to its highly penetrative gamma rays.
Technetium-99m Detection of abnormities in the blood, heart and various other organs
Imaging of organs and glands
Pinpoint cancer growths; location and sizes
Iodine-123 Treatment and Diagnosis for thyroid diseases and other thyroid disorders
Xenon-133
Study of the blood circulation especially in the brain
Ventilation for the lungs and other pulmonary processes

Strontium-85 Close study of the bone functions, structure and formation
General metabolism functions

g) Discuss how the dangers and problems associated with using radioisotopes in medicine compares with using them in industry.
The use of radioactive isotopes is always going to be a threat to life no matter where the application is. In medical uses, patients are constantly being beamed by radiation would be likely to have some tissues damaged by it. However, in terms of medical usage, it is relatively safer compared to industrial applications. Here, a lot of workers and other operators may be exposed to a lot of radiation in their work places. Radiation is hazardous and would cause cancer and other tissue problems if exposed too much. Because in medical uses, the amount of radiation is always monitored and checked, it is safer in comparison to work where radiation leaks may be unknown.

Bibliography
Question 1 – Biopolymer: http://edis.ifas.ufl.edu/AE210 Question 2 – Ethanol from Sugar Cane:
1. http://www.sundyne.com/ind/details/1,,CLI1_DIV92_ETI8070,00.html
2. Surfing Chemistry HSC – 15 Manufacture of ethanol – page 23

Question 3 – Ethanol Fuel:
1. http://hsc.csu.edu.au/chemistry/core/identification/chem923/chem923net.html#sylla14
2. http://en.wikipedia.org/wiki/Ethanol#Prospective_technologies
3. http://www.abc.net.au/catalyst/stories/s1763365.htm
4. http://www.environment.gov.au/atmosphere/fuelquality/publications/ethanol-limit/background.html
5. Surfing Chemistry HSC – 16 Ethanol as a Fuel - page 25 (teacher handout)
6. 2 Unit Chemistry HSC Course 2005/06– Production of Materials (Module 9.2) Work booklet notes and questions (another teacher’s handout) pages 23, 5.31-5.33pp
7. Longman Sciences Chemistry Contexts 2 – Chapter 3 Ethanol – page 47
8. Conquering Chemistry HSC Course – Chapter 1.17 – Page 30 - Ethanol as a Fuel
9. http://en.wikipedia.org/wiki/1973_oil_crisis
10. http://www.eia.doe.gov/emeu/cabs/Brazil/Oil.html

Question 4 – Batteries: http://en.wikipedia.org/wiki/Dry_cell http://www.corrosion-doctors.org/PrimBatt/images/01zncL.jpg - image http://www.physchem.co.za/Redox/Cells.htm Question 5 - Discovery of Elements
1. http://en.wikipedia.org/wiki/Discovery_of_the_chemical_elements
2. http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/cyclot.html
3. http://en.wikipedia.org/wiki/Cyclotron
4. Longman Sciences Chemistry Contexts 2 – Chapter 5.4 production of radioisotopes – page 107
5. http://www2.slac.stanford.edu/VVC/accelerators/circular.html

Question 6 - Radioisotopes:
1. 2 Unit Chemistry HSC Course 2005/06– Production of Materials (Module 9.2) Work booklet notes and questions (another teacher’s handout) pages 5.62-5.63 - Radiation Detection
2. Surfing Chemistry HSC – 24 Uses of Radioisotopes page 39 (teacher handout)
3. http://hsc.csu.edu.au/chemistry/core/identification/chem925/925net.html#net8
4. http://en.wikipedia.org/wiki/Technetium-99m
5. http://193.71.11.91/public/medical/nuclear5.shtml
6. Longman Sciences Chemistry Contexts 2 – Chapter 5.5 - Uses of Radioisotopes – page 114
7. http://www.epa.gov/radiation/radionuclides/cobalt.htm#properties
8. http://en.wikipedia.org/wiki/Cobalt-60
9. Jacaranda Physics 2 HSC Course - From Quanta to Quarks - Chapter 25.5 Medical and Industrial Applications of Radioisotopes - page 498-499

Question 7 – Issues with Radioisotopes:
1. http://en.wikipedia.org/wiki/Radiography
2. Jacaranda Physics 2 HSC Course - From Quanta to Quarks - Chapter 25.5 Medical and Industrial Applications of Radioisotopes - page 498-499