science gcse core, additional and triple science powerpoints

1. Material choices Route map Over the next 12 lessons you will study : Friday 21 October 2011 C2.1 Choosing the right stuff C2.2 Polymers everywhere C2.3 Testing times C2.4 Zooming in End of module test C2.5 The big new idea C2.6 Molecules big and small C2.7 Designer stuff C1.8 Smart materials C2.9 Is it sustainable C2.10 Life cycle assessment C2.11 Life cycle of a synthetic polymer C2.12 Assessing environmental impact

3. C2.7 Decide whether the following statements are true or false: Introduction: Some polymers (synthetic or man made) are naturally soft, in fact too soft to be useful. Scientists can harden polymers like rubber by adding cross links between the rubber chains making it stronger and more resistant to heat. Charles Goodyear in 1840 first discovered how to vulcanise natural rubber making it suitable for use in tyres. Other polymers are naturally too hard, PCV used for clothing has plasticisers added to it to soften it. Extension questions: 1: Explain why formula one tyres will have less cross linking when compared to normal car tyres ? 2: Give 3 uses for high density hard PVC, for example guttering ? 3: Cling is now made form PVC, do you think this type of PVC has lots of plasticizers added to it ? 4: Explain why a child’s teething ring made from PVC has to be soft ? 5: Explain why adding cross links help to harden a polymer ? Know this: a: Know that the properties of polymer like PVC can be change by cross linking or adding plasticisers. b: Know the products that require soft ad hard plastics. Friday 21 October 2011 Designer stuff

4. Key concepts Look at the photograph and information and answer all the questions: Plasticizers are added to HDPVC to form LDPVC. How does the addition of the plasticizers molecules soften the HDPVC ? The plasticizers molecules found in cling film (LDPVC) can move form the film to the food. These molecules are toxic. Should the government ban the use of cling film ? C2.7 a Softening plastics like PVC To give plastics like PVC plasticity and to expand the range of the rubbery (high-elastic) state, plasticisers are added during manufacture. This leads to a reduction in intermolecular interaction and to a change in a number of physical properties of the polymer. Above all, deformability increases with a certain reduction in strength and hardness, and also there is a reduction in the softening point and melting point of the material. HD PVC LD PVC chains plasticizers

5. C2.7 b Look at the photograph and information and answer all the questions: PVC is one of the most widely used plastics in the world. It offers a diverse and varied range of properties, and contributes significantly to the modern lifestyles that we all enjoy. PVC is a very durable and long lasting construction material, It is also used to make clothing and waterproof coats as well as double glazing and guttering for collecting rainfall. Give three other uses of high density PVC (hard) and low density PVC (soft) ? Look at the picture of the vinyl chloride chains in both the hard and soft form. Explain how by adding the plasticizers (yellow), the PVC softens ? Give three other polymers like PVC where scientists alter the density of the polymers by cross linking or adding plasticisers ? HD PVC High and low density PVC LD PVC Key concepts

6. Key concepts C2.7 c Look at the photograph and information and answer all the questions: The properties of any polymer are determined by two things. a) The length of their chains b) How the fibres interact with one another Scientists can change properties like strength and elasticity by using different catalysts that they use during polythene manufacture. HDPE LDPE PET Cling film In cling film, the polymer chains mostly branched giving a low density. How does introducing ‘cross link’ change the properties of the polythene ? In PET plastic which is used to make drinks containers, the fibres line up end to end allowing high density plastic. Why is this an ideal property for a drinks container ? Catalyst B Catalyst A Using different catalysts in manufacturing plastics

7. C2.7 Plenary Lesson summary: hard rubber cross PVC Friday 21 October 2011 Charles Goodyear (December 29, 1800 – July 1, 1860) was the first American to vulcanize rubber, a process which he discovered in 1839. Although Goodyear is often credited with its invention, recent evidence proves that the Mesoamericans used stabilized rubber for balls and other objects as early as 1600 BC. How Science Works: Research into the use of Gort-tex, Velcro and Kevlar Preparing for the next lesson: Soft polymers like _________ can be hardened by adding _______ links between their long chains. This help to stabilises the product. _______ polymers like ______ can be softened by added plasticisers. This help interfere with how the long chains fit against one another. Decide whether the following statements are true or false : False True 3: Rubber used in tyre would be too soft if it were not altered by chemists ? False True 2: Cross linking polymer changes reduces a polymer’s hardness ? False True 1: The density and hardness of PVC can be chemically altered by plasticisers ?

9. C2.8 Decide whether the following statements are true or false: Introduction: Scientists are now able to manufacture some very smart material using polymers. Gor-tex ® This is a thin membrane made form PTFE (used to also make non stick pans) which contains millions of microscope hopes which allows water vapour out and prevent rain from coming in therefore keeping you dry Kevlar ® This is a very strong polymer that is five time stronger than steel and is used to make bullet proof vests and sport equipment like tennis rackets Velcro ® This uses nylon hooks and loops to mimic how thistle and other seeds attached themselves to animal fur. Extension questions: 1: The makers of Gore-tex claim that it behaves like ‘human skin’ in keeping out rain and letting water vapour out. Why is the a) a good analogy to how Gore-tex works and b) what would happen to you if your waterproof didn’t let water vapour out ? 2: Give three uses for Kevlar and Velcro ? 3: Try an image a smart material that you would like to see being invented and explain its use and general properties ? 4: Explain why Kevlar is not used to make building and bridges despite being stronger than steel gram for gram ? Know this: a: Know that scientist can now products very exotic materials using polymers like nylon, Kevlar and PTFE. b: Know how these polymers re used in high tech high end products. Friday 21 October 2011 Smart materials

10. Key concepts Look at the photograph and information and answer all the questions: What (found in nature) inspire material scientists to design Velcro® ? C2.8 a Smart materials ….Velcro® Velcro ® is a brand name of fabric hook-and-loop fasteners. It consists of two layers: a "hook" side, which is a piece of fabric covered with tiny hooks, and a "loop" side, which is covered with even smaller fibres. When the two sides are pressed together, the hooks catch in the loops and hold the pieces together Look at the picture above left. Give three uses for Velcro and explain why it is an essential designer material ?

11. Key concepts Look at the photograph and information and answer all the questions: The holes in the PTFE membrane are about 10,000 times smaller than a rain drop would they be large than a single molecules of water ? C2.8 b Smart materials ….Gortex® Gore – tex ® fabrics are made by laminating a PTFE polymer membrane to durable textiles. The membrane has millions of tiny holes which prevent rain from getting in but allow water vapour out. It performs like human skin ! William Gore who invented and patented Gore-tex® has made many millions keeping the nation dry by selling waterproof Explain why a cheap plastic waterproof made form PVC or polythene performs less well than a waterproof made form Gore-tex ?

12. C2.8 Plenary Lesson summary: kevlar fasten chemically materials Friday 21 October 2011 How Science Works: Preparing for the next lesson: Polymers like ________, PTFE and nylon can be used in modern _________ which have some very unique properties. Scientists are able to ___________ alter polymers so they keep us dry, protect our bodies and even ______ object to one another. The scientists who invented Velcro using modified nylon was called George de Mestral. He looked at how seeds like thistle attached themselves to animal fur. This help the seed to become dispersed away from the maternal plant. He made his fortune replicating nature and gave the World Velcro. Research into the sustainable use of natural resources like wood, crude oil and soil Decide whether the following statements are true or false : False True 3: Kevlar is used instead of steel because it is stronger and lighter ? False True 2: Velcro uses nylon ‘hoops and hooks’ ? False True 1: Gore-tex was invented by William Gore in the 1980s?

14. C2.9 Decide whether the following statements are true or false: Introduction: Natural resources like forests and woods need to be used in a sustainable way to preserve the environment, vital habitats for other plants and animals and the supply of these resources for future generations. Trees particular tropical hard wood trees can take many hundred of years to grow but only a few years to cut down and harvest. Each year, forest equivalent to all of Wales is cleared form the Amazon jungle Extension questions: 1: Explain how by using plastics like PVC for windows and other products can help reduce the need for natural resources like wood ? 2: An average pine forest contains about 10,000 trees. A pine tree takes between 20 to 30 years to grow. A logging company wants cut down and sell 2,000 trees a year. They also promise to replant these 2,000 trees with saplings. Are they using the wood sustainably and explain your answer ? 3: We all use fossil fuels like coal, gas and oil. Explain why the use of these resource is not sustainable ? Know this: a: Know that sustainable development protects the environment and the future supply of that resource. b: Know that unsustainable development has a heavy cost on the environment. Friday 21 October 2011 Is it sustainable

15. C2.9 a Look at the photograph and information and answer all the questions: It is estimated that the crude oil we use in a single year will take the Earth one million years to form. Explain why then crude oil is called a finites resource ? About 4 to 6% of the World’ crude oil is used to make plastic. This is greater than the whole of Africa uses every year. How can increase the sustainability of plastic ? 300 million years Unsustainable use of crude oil Oil Crude oil Plastic pellets End product The road from crude oil to finished plastic product has numerous many steps. 1. Crude oil and natural gas are refined into ethane, propane, hundreds of other petrochemical products 2. Ethane and propane are combined with catalysts to form long chains called ethylene or propylene. These long molecules resemble fluff. 3. Fluff is combined with additives in a continuous blender. 4. Polymer is fed to an extruder where it is melted. 5. Melted plastic is cooled then fed to a pelletizer that cuts the product into small pellets. 6. Pellets are shipped to customers. Key concepts

16. C2.9 b Look at the photograph and information and answer all the questions: A pupil was given a tree that was dug from the ground. The pupil was then asked to explain what had caused the mass of the trr to change over time ? Oak takes about 100 years to mature form acorn to tree, pine only 20 years. Explain why pine is now considered a more sustainable source for timber ? Explain why plastic like PVC and polythene can help reduce the demand for wood and paper ? Sustainable logging is the practice of taking only some trees, in ways which cause the least amount of harm. At the same time, some large trees are kept as shade and habitat for animals. Sustainable logging also ensures the forest remains, which also ensures the jobs of the loggers. If we clear-cut all our forests (in the US), we would probably run out of lumber in 15-20 years. 100 years Sustainable use of natural resources sapling oak tree timber end product Key concepts

17. Key concepts Look at the photograph and information and answer all the questions: In 1774 Captain Cook landed on Easter island and witness a handful of islanders near to starvation. Explain why they were stuck on the island ? Explain why chopping down the wood and tress on Easter island led to the rapid erosion of the top soil ? C2.9 c Death and starvation on Easter island Easter island has served as a cautionary tale about the dangers of overexploitation .Trees are sparse on modern Easter Island and it has been argued that the native Easter Islanders deforested the island in the process of erecting their statues and in providing sustenance for an overpopulated island. No longer able to build boats and with soil erosion because of a lack of tree roots, these pressure would have reduce food production causing starvation and death.

18. C2.9 Plenary Lesson summary: prosperity raw resources depleted Friday 21 October 2011 Prior to the iron age there was a saying in the UK that a squire could go from the west to the east coast without ever touching the ground. During the iron age where charcoal made from timber was required in huge quantities and forest were cleared for livestock, pasture and crops, we as a nation felled and cleared many thousands of acres of forest that have never returned. How Science Works: Research into the life cycle of a product form its manufacture, use and disposal. Compare the life cycle of an iPod to a piece of furniture to a plastic bag Preparing for the next lesson: Natural _________ like wood are always at risk of being __________ if they are not used in a sustainable manner. Ensuring that we continue to have _____ materials for future generations is very important if the economic _________ continues. Decide whether the following statements are true or false : False True 3: Recycling and reusing raw materials can reduce the demand for raw materials ? False True 2: Using resources like wood in a sustainable way ensure future supplies ? False True 1: Oil. Coal and natural gas are impossible to use sustainably ?

20. Decide whether the following statements are true or false: Introduction: We are surrounded by many hundred of consumer goods including iPods, LCD TVs clothing and footwear. The life of each of these products have three distinct phases: Cradle Use Grave Each product is required by law to undergo a life cycle assessment, with the aim to reduce the rate at which we use natural resources, the energy we need to run the product and the waste produced when the product is disposed of Extension questions: 1: Give two examples where we can a) reuse products b) recycle products and c) reduce product quantities that we use everyday ? 2: Take an ordinary glass bottle made form sand and limestone. Think about its life cycle. Give a brief account of its manufacture, use and disposal ? 3: Think of a so-called ‘environmentally friendly product. Describe how designers have reduce its impact on the environment ? 4: Should products made from plastic have a disposal tax as part of the cost of its purchase ? Know this: a: Know that any product has three distinct phases: Cradle, Use and Grave. b: Know that designers now have to asses the impact of any products at each phase of its life cycle. Friday 21 October 2011 C2.10 Life cycle assessment raw materials require energy used to make it energy required to use energy required to maintain it chemicals needed to maintain it energy needed to dispose of it space needed to dispose of it

21. C2.10 a Look at the photograph and information and answer all the questions: Here in the Europe, our consumer lifestyles means that we use lots of natural resources and produce lots of waste or rubbish. A large percentage of UK households still do not recycle, reduce or reuse in their everyday lives. Most people over consume, fail to reuse or recycle everyday objects. By recycling, reducing and reusing we can lessen our environmental impact. Plastic especially in packaging is often used only once and then buried in land fill sites...suggest one way you can reduce the amount of plastic you use ? Suggest one product that you can a) reuse and b) recycle ? Used plastic that is buried in landfill sites takes many years to breakdown. Scientists have now developed biodegradable plastics. Do you think that all plastics now sold should be biodegradable ? Key concepts

22. Key concepts Look at the photograph and information and answer all the questions: Explain why it is more environmentally friendly to recycle plastic when compared to the alternatives of burial (landfill) or incineration ? How can companies and local council and families be encouraged to recycle their plastic waste ? C2.10 b Life cycle assessment of plastic packaging Plastic is one of the most versatile synthetic materials, it also extremely environmentally unfriendly. There is no doubt that plastic places a strain on the already depleting resources. Consider this - a single plastic bottle may be used for hours only but takes about 1,000 years to break down completely when land filled. As plastic's recycle rate around the globe is very low, its carbon footprint includes incineration and land filling. Plastic trash is also causing heavy pollution on beaches and oceans around the world. Manufacture Disposal

23. C2.10 Plenary Lesson summary: natural reused life short Friday 21 October 2011 WEEE which stand for Waste Electrical and Electronic Equipment is legislation introduced recently by the UK government to reduce the impact of electrical waste on the environment. We now have to pay for the disposal of electrical goods like fridges, washing machines and dryers. If manufacturers recycle certain components and raw materials the manufacturer is entitled to a tax refund. How Science Works: Research into the life cycle of synthetic polymers like polythene and PVC Preparing for the next lesson: All products have a _____ cycle, some are _________, some are very long. When new products are made and used they consume _________ resources and energy. When they are disposed the can either be recycle, ______, land filled or incinerated. Decide whether the following statements are true or false : False True 3: Within 10 years you will pay for each kilogram of waste that you produce ? False True 2: The UK government now requires all councils to recycle 25% domestic waste ? False True 1: Landfill is an environmentally friendly option for disposing of waste ?

25. Introduction: Plastics and synthetic polymers are everywhere. The life cycle of a supermarket polythene bag like any product has of three distinct phases: Cradle Use Grave Shops are now charging up to £0.10 for each bag in order to encourage us to reuse our polythene bags C2.11 Extension questions: 1: Estimate how many plastic bags you and your family use and dispose of every a) week and b) year ? 2: Compare the life cycle of a plastic bag and a plastic drinks bottle. Are they similar or completely different ? 3: List three other product that use plastic which has a very short life cycle ? 4: Do you think the government should tax us when we use a plastic bag to carry our shopping home ? Know this: a: Know the life cycle of a synthetic polymer. b: Know how we can reduce the need for raw materials by encourage recycling and reusing of a product. Friday 21 October 2011 Life cycle of a synthetic polymer Approximately 4% of World’s crude oil is used for the manufacture of polythene bags (raw materials and energy) Polythene bags have to be transported to shops and super-markets where they are sold to the consumers. A polythene bag has a average ‘use time’ of about 3 hours. It can then be recycled, reused, or dumped by landfill or incineration.

26. Key concepts C2.11 a Look at the photograph and information and answer all the questions: An industrial chemist will always consider and try and control the costs of every part of the industrial process from the cost of buying in raw materials to the cost of turning them into a new product. Chemists must also include the cost of disposing of waste chemicals and the cost of energy (heat and electricity) require during the manufacturing process. Yield % Product The price of crude oil begins to soar, what cost associated with the process above will begin to rise ? If all plastics are made from crude oil could burning them once used and using this energy to make electricity be an environmentally friendly option ? Raw materials Material cost (£) Transport cost (£) Waste cost (£) Process cost (£) Electrical cost (£) Heating cost (£) Product cost (£) Transport cost (£) Waste cost (£) Manufacture Reducing costs from raw material to final product

27. Key concepts C2.11 b Look at the photograph and information and answer all the questions: Look at the process above, explain whether this is open loop or closed loop recycling ? Give three ways that we can encourage individuals and households to recycle more of their PT plastics ? PET plastic are made using crude oil. 1. Crude oil and natural gas are refined into ethane, propane, hundreds of other petrochemical products 2. Ethane and propane are combined with catalysts to form long chains called ethylene or propylene. These long molecues resemble fluff. 3. Fluff is combined with additives in a continuous blender. 4. Polymer is fed to an extruder where it is melted. 5. Melted plastic is cooled then fed to a pelletizer that cuts the product into small pellets. 6. Pellets are shipped to customers . Making PET (1) plastics Crude oil

28. C2.11 Plenary Lesson summary: short food waste natural Friday 21 October 2011 Enjoy synthetic polymers while you can ! The raw materials and the source of entry to make these polymers is of course crude oil. With only 50 years of supply left, in your life time you may be one of the last person to use a polythene bag to carry your shopping home from the supermarket. How Science Works: Research into ‘is it better and more environmentally friendly to use paper or china plates on a daily basis Preparing for the next lesson: Most plastics used in the _____ industry and a very _____ life cycle and contribute up to 8% of our domestic _____ that is taken to landfill sites across the country. Such a short life cycle is a waste of our _________ resources and our energy. Decide whether the following statements are true or false : False True 3: In landfill sites, plastic take many centuries to rot and decompose ? False True 2: When crude oil runs out, bulk polythene manufacture will cease ? False True 1: A bag made from cotton which can be reused is environmentally friendly ?

30. C2.12 Decide whether the following statements are true or false: Introduction: Take a simple every day item like a dinner plate. Is it more environmentally friendly and therefore less impacting to use ‘once use disposable plates or regular china plate made form clay, fired and then washed between each use. By doing a full life cycle assessment form cradle to grave we can determine the impact for each product and make an informed choice. Extension questions: 1: Compare how a disposal ‘one use’ paper plate and a regular china plate is made ? And which uses the leas a) natural resources ad b) energy during its manufacture ? 2: A china plate requires washing between each use, which is more impacting a) using a dishwasher or b) hand washing. 3: When we dispose of the paper plate what happens to the plate over time when it is place in a land fill site ? 4: Compare the raw materials and energy used during the use of a disposable one use paper plate and a regular china plate ? Know this: a: Know the environmental impact of a products. b: Know how to compare the life cycle of different products. Friday 21 October 2011 Assessing environmental impact

31. C2.12 a Look at the photograph and information and answer all the questions: Is it better to use disposable paper plates or regular china plates that require washing ? Reuse is always best, paper plates require trees, energy, and water to manufacture. They also have to be transported to the shops and your home. regular plates on the other hand after their manufacture, use only water, soap and energy with NO landfill waste generated. A china plate can be reused many thousands of times. At the cradle stage (manufacture) which uses more resources in terms of raw materials and energy, the paper or china plate ? Make a comparison of the difference in the life cycle of a china plate versus a paper plate ? Is burning paper products like disposal plates better for the environment when compared to simply putting them in a landfill site ? Should we use paper or china plates china plates paper plates reuse disposal reuse one use Key concepts

32. Key concepts Look at the photograph and information and answer all the questions: C2.12 b Disposable wet wipes.... better or worse for the environment ? Recent developments like high raw material (such as petrochemicals) costs and increased sensitivity to environmental concerns have made the use of short lived disposable products like wet wipes very environmentally friendly. Most families want to live ‘green’ reducing the use of raw materials, energy and waste. Is the alternative better though if families use clothes that they have to wash instead of wet wipes ? raw materials manufacture product use disposal Are the raw material sustainable or unsustainable / What are the manufacturing costs ? Is the yield as high as possible ? How is the product brought to the consumer and how is it used ? yield How is the material disposed ? The process Questioning the process Compare the life cycle of a cloth that is used and washed and then reused and the life cycle of a single wet wipe. The amount of energy required to produce a single wet wipe is 0.2 kWh. The amount of energy to wash a cloth is 0.4 kWh. Explain why a wet wipe may be more environmentally friendly based on this data alone ?

33. C2.12 b Look at the photograph and information and answer all the questions: New products have to be designed and engineered from cradle to grave which also includes “a life cycle assessment. The impact of raw material resources used in the manufacture of a product, the energy used to make and maintain it as well as the ultimate fate (disposal) of the product when it enters the waste stream have to be factored into the design of the product. Explain why we cannot use crude oil and other fossil fuels in a sustainable way ? Scientists say that it takes more cruse oil to transport a plastic bag to a landfill site than it does to make one. Explain what they mean by this statement ? Give three other uses of crude oil, other than as a raw material for the manufacture of polythene ? Life cycle of synthetic polythene crude oil PET plastics tyres PVC landfill Key concepts

34. C2.12 Plenary Lesson summary: supplies impact prodcuts resources Friday 21 October 2011 The green market for environmentally friendly products is now worth a staggering 15 to 20 billon pounds. These products are usually more expensive to buy and claim to use less raw materials and energy during their manufacture, use and disposal. Some so called green products are no better than normal products so care should always be taken when choosing the right product How Science Works: Preparing for the next lesson: Knowing the full life cycle and environmental _______ of everyday _________ helps us to chose the most environmentally friendly products so we can help preserve our natural _______ and energy _________. Revise for your end of module test: use www.bbc/bitesize.co.uk , your text books and your exercise books Decide whether the following statements are true or false : False True 3: All products that we use and buy have some form of environmental impact ? False True 2: Hand washing uses less water and energy compared to using a dishwasher ? False True 1: Using paper plates is more environmentally friendly ?