AQA GCSE Science: C1b 4.1 Are you beginning to crack?? Lesson 4 is a computer lesson so remember to book a lab!!!! AQA Specification Link • Hydrocarbons can be broken down (cracked) to produce smaller, more useful molecules. This process involves heating the hydrocarbons to vaporise them and passing the vapours over a hot catalyst. A thermal decomposition reaction occurs. • The products of cracking include alkanes and unsaturated hydrocarbons called alkenes. Alkenes have the general formula CnH2n and can be represented in the following forms: – C2H4. –H H H [ [ [ H–C–C=C [ [ H H Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Special needs. The cracking • Reasons for cracking Lesson structure practical may be too difficult large hydrocarbon Starter for students with poor manual molecules and how it is Comparing – On the board, draw the structural formulae of ethane and ethene. Ask the students to list the dexterity; this could be carried out. similarities and differences. [Similarities: Same number of C atoms / H atoms all have one bond / C atoms all have completed as a demonstration • That alkenes contain 4 bonds / both are hydrocarbons. (5 minutes) Differences: Different number of H atoms / ethane is saturated, ethene instead. double bonds and are called is unsaturated / ethane has C - C but ethene has C=C.] • Learning styles unsaturated hydrocarbons. Chemical formula – Ask the students to use the general formula for an alkene to work out the molecular and Kinaesthetic: Completing the displayed formula if n =2, 3, 4 [C2H4, C3H6, C4H8]. (10 minutes) practical. Visual: Making a poster Recap – Ask students to consider the phrase ‘thermal decomposition’ (recall limestone work). Ask them to define it highlighting the differences and give an example [using heat to break down a substance, heating of calcium carbonate]. (10 minutes) between alkanes and alkenes. Intrapersonal: Completing Main their own creative writing. Teacher Expo: Interpersonal: Reflecting on Make links between fractional distillation from previous module, and where cracking fits in. Breaking the molecular re-arrangement up the larger fractions into small more useful molecules. Lead through the practical worksheet. that takes place in cracking. • Cracking can be done at a laboratory scale in the classroom. Groups of about three are best, as one student can heat • Homework. the boiling tube, and often it takes two students to collect the gas over water. W\sheet C1b4.1 – how can • Bromine water can be used to test the product and contrast this with the reactant. Ethene is flammable; this can be we distinguish alkenes from demonstrated by putting a lighted splint into the test tube and a flame should be seen travelling down the tube (eye alkanes. protection must be worn). The flame should be smokier than the equivalent alkane (ethane) as there is a higher percentage of carbon. Pupil Development Pupils crack medicinal paraffin and collect and test the products. Pupils need to complete the worksheet and answer the question appropriately • ICT link-up. If you have a • Students often find the idea of atoms rearranging themselves during chemical reactions a difficult concept. web cam you might film the Encourage the students to imagine that they are a carbon atom in a molecule of paraffin. They could then write a cracking experiment for a creative story about their journey from being in paraffin, through being cracked and finally being tested with later discussion on what bromine water. happens. The • For lower attaining students, statements of each ‘scene’ could be given. Then students put them into the correct Interactive/Simulation C1b order and then draw a cartoon/picture to represent that section of the story. 4.1 ‘Cracking of • Some students can find it difficult to notice the differences between alkanes and alkenes. Encourage them to hydrocarbons’ helps students compare alkanes and alkenes in terms of their structures and how to test them. They could be given a piece of visualise how the atoms can coloured paper to fold in half and make a poster comparing the two families of hydrocarbons. be rearranged. Don’t use not very good! Plenaries • Teaching assistant. Split Look at pupil book page 184 and go through the equations and make sure the worksheet is completed successfully. the class into two groups. The Faster workers could answer question 3 on page 185. . (10 minutes) teacher and teaching assistant can then help small groups to test for alkenes. Learning Outcomes Practical support Activities and All students should be able to: Cracking extensions Visually identify alkanes and alkenes Equipment and materials required • Students could be asked to and also say which one has the Bunsen burner and safety equipment, S-shaped delivery tube (with bung on one end and Bunsen valve explain why bromine water double bond. on the other), pneumatic trough, boiling tube, mineral wool, three test tubes with bungs, test-tube rack, decolourises in alkenes and to stand, boss and clamp, a hydrocarbon (medicinal paraffin, petroleum jelly or decane – flammable), display the reaction using broken ceramic pot/aluminium oxide powder (catalyst), bromine water (irritant and harmful – see molecular modelling kits. Most students should be able to: CLEAPSS Hazcard 15). • Explain why cracking is carried out. • Students could be given the Details chemical formula of decane, • Write a word equation for the cracking Soak the mineral wool in paraffin and put at the bottom of the boiling tube. About 2 cm from the bung and asked to generate as reaction. put in the catalyst (about 1 spatula full) and clamp in position. Heat the catalyst strongly (with a blue many balanced equations as • Recognise an alkene from a structural or flame), then flash the flame towards the mineral wool, so that the hydrocarbon evaporates and reaches possible to demonstrate all the molecular formula. the catalyst. Students should collect the gas over water. The Bunsen valve will help prevent suck back possible combinations of • State and carry out the test for alkenes. within the apparatus but get students to remove the end of the delivery tube from the trough of water alkanes and alkenes that could by lifting the clamp stand as soon as they finish heating. Eye protection should be worn throughout. be generated in the cracking Some students should also be able to: The collected gas can be tested with bromine water (as detailed below). The gas collected is highly • Write a balanced symbol equation to reaction. flammable and this can be demonstrated by igniting it with a burning splint in the test tube. • Students could use the represent cracking. • State and use the general formula to bromine water test for Risk Assessmet margarine. They should find work out a molecular formula when n is General lab rules apply – goggles and care when heating alkane. Medicinal paraffin, petroleum jelly that the margarine given. or decane – flammable. Bromine water (irritant and harmful – see CLEAPSS Hazcard 15). decolourises the bromine Need to re-iterate the fact that they must remove the delivery tube from the water when they stop water, showing that it is heating to prevent suck back into the boiling tube which could crack the tube. unsaturated. AQA GCSE Science: C1b 4.2 Pretty poly (How can you link a parrot to chemistry?) AQA Specification Link • Alkenes can be used to make polymers such as poly(ethene) and poly(propene). In these reactions, many small molecules (monomers) join together to form very large molecules (polymers). Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the social and economic advantages and disadvantages of using products from crude oil as fuels or as raw materials for plastics and other chemicals • to evaluate the social, economic and environmental impacts of the use, disposal and recycling of polymers. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Gifted and talented. The idea • That monomers join Lesson structure of another type of polymerisation together to make polymers. Starter – condensation – could be • About some uses of Odd one out – On the board, write: ‘protein, rubber, DNA, polyethene’. Ask the students to name the odd one introduced. Students could then polymers. out. [All of these are polymers, but polyethene is not a naturally occurring polymer.] (5 minutes) make nylon (this is a condensation polymer and is not Main on the specification). A recipe for Teacher expo this is in Classic Chemistry • Students often struggle with drawing the structures of monomers and polymers and how they relate to each Demonstrations (RSC). other. Provide students with structural formulae of ethene, chloroethene and tetrafluoroethene; illustrate how the • Learning styles simple alkene is joined to other alkenes (monomers) to make the polymers. Kinaesthetic: Making models of • Students could then record the names and structural formula of each monomer and polymer couple. polymers. • A kinaesthetic approach to polymerisation would be to use paperclips to visually present how the monomers Visual: Observing how the join together – give pupils a few examples of monomers and polymers and pupils give the other half on the monomers change their bonds to couple. become polymers. • Show or have students use the Interactive C1b 4.2 ‘Making polymers’. Here they can see the process of Auditory: Listening to students joining monomers as well as appreciate that different monomers can be involved. explain their polymer models. Pupil development Interpersonal: Working in groups to make their own molecular model of ethene and then making a model of poly(ethene) from their individual models. Intrapersonal: Appreciating the bond breaking and making a model of polymerisation. • Homework. For polyethene and Plenaries polypropene, find two uses and Matching – Ask the students to generate the polymer names from these monomer names: explain which property makes it – suitable for that application. – – – • ICT link-up. Show the students – an animation of simple addition polymerisation. Learning Outcomes Practical support Activities and extensions Most students should be able to: Modelling polymerisation • Students could be encouraged to • State definitions of monomers and polymers. Equipment and materials required look at the industrial production • Determine the polymer name if the monomer name is given. Molecular model kit(s). of polymers. Videos are available • Determine the monomer name if the polymer name is given. Details on Industrial Chemistry (RSC). • List some uses of polymer products. On the board, draw the structural formula of ethene. Ask each group of students to make an Some students should also be able to: ethene molecule. Then take two molecules and • Draw the structural formula of a polymer if the monomer is given. explain that when they are heated with a • Explain polymerisation in terms of bond breaking and making. catalyst the double bond breaks (show this on the two models) and the molecules join up (join the two monomers). Get each group to add their monomer onto the growing polymer chain. Explain that scientists are interested in the structure but don’t draw the whole chain, as it is thousands of atoms long. Ask the students to suggest what could be done to show this. Explain that the repeating unit is drawn; ask a student to draw this on the board. Then explain that this is shown in brackets with an ‘n’ to show that it is repeated lots of times. KEY POINTS AQA GCSE Science: C1b 4.3 Plastic fantastic AQA Specification Link • Polymers have properties that depend on what they are made from and the conditions under which they are made. For example, slime with different viscosities can be made from poly(ethenol). Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the social and economic advantages and disadvantages of using products from crude oil as fuels or as raw materials for plastics and other chemicals • to evaluate the social, economic and environmental impacts of the use, disposal and recycling of polymers. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: Lesson structure • Special needs. For these students, • that different plastics are used Starter only choose two plastics – one for different jobs due to their Define – Ask the students to use the Student Book to find out what the two groups of plastics are and thermosetting and one properties. what property is used to distinguish between them. [Thermosoftening plastics can be re-heated to thermosoftening to complete the To draw a conclusion that is become pliable and can be re-moulded, whereas thermosetting plastics will char before they melt.] (5 practicals on. scientific from simple minutes) • Learning styles experimental data. Kinaesthetic: Carrying out a Main practical. Teacher Expo Visual: Completing a card sort Link to starter – thermo – property of plastic. Give pupils a selection of plastics in a tray and about polymers in order to generate some thermosoftening plastic and they explore the properties. Thought shower the ideas a table. pupils come up with. Auditory: Listening to information to guess their materials. • Students could experiment with the consistency of slime made with PVA glue (poly(ethenol)). The Interpersonal: In groups, handling polymer strands are H-bond cross linked with borate groups. This cross linking is not permanent and different polymers and discussing most of the space in the gel is taken up with water molecules. This makes it a pliable polymer. which classification they would fall • Adding different amounts of borax changes the number of cross-links; the more there are, the stiffer the into. polymer. Ask the students to design and conduct an experiment to find out the effect of adding different Intrapersonal: Finding different amounts of borax to PVA glue. (This relates to ‘How Science Works’ – designing an investigation.) names for PVC. Pupil development • Homework. Find the names and Pupils link what they feel and see to a property and how it can be used in a constructive way. uses of two different plastics – one Pupils carry out a small investigation as described above. Worksheet will give instruction of initial thermosetting and one quantities to be used. The aspect of investigation to be concentrated on is drawing a conclusion from the thermosoftening. results obtained and linking this to properties of plastics. Plenaries Conclusion - write a brief description of what you did and then write a full SCIENTIFIC conclusion that you have come to.(10 minutes) Learning Outcomes Practical support All students should be able to: Making a polymer Carry out a simple experiment to gain a set of results. Equipment and materials required 100ml measuring cylinder, 250 ml beaker, dropping pipettes, hot plate, stirring rod, 4g PVA glue, 4g Most students should be able to: borax (irritant), eye protection, (food colouring). • Explain why a given plastic is fit for a purpose. Details Before the lesson, make up a solution of borax, with 100 ml of warm water in a beaker with the borax. Some students should also be able to: Students should wear eye protection when using borax solution. The solution may need to be warmed for • Explain how the intermolecular forces between the polymer molecules it to fully dissolve. Put 100 ml of water into the 250ml beaker and heat gently. Add 4g of PVA slowly, in plastics affect their properties. while stirring, the mixture must not boil. When all the PVA has dissolved, remove from the heat, and add a few drops of the borax solution and stir. If too much borax is added, the polymer will be brittle, if not enough is added the slime will be runny. Food colourings can be added to make slime of different colours. This should be done before the borax is added. In time, the slime will dry out. Students can handle the slime, but should wash their hands afterwards, and eye protection should be worn throughout. Equipment list. Risk Assessment AQA GCSE Science: C1b 4.4 Are you as smart as a polymer?? COMPUTER LESSON AQA Specification Link • Polymers have many useful applications and new ones are being developed, for example: new packaging materials, waterproof coatings for fabrics, dental polymers, wound dressings, hydrogels, smart materials, including shape memory polymers. • Many polymers are not biodegradable, so they are not broken down by microorganisms, and this can lead to problems with waste disposal. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the social and economic advantages and disadvantages of using products from crude oil as fuels or as raw materials for plastics and other chemicals • to evaluate the social, economic and environmental impacts of the use, disposal and recycling of polymers. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Learning styles • That there are new polymers Lesson structure Kinaesthetic: Completing tests on being developed and being Starter different materials. used in innovative ways. Monomer or polymer – Ask the students to categorise the following statements as monomers or polymers. Visual: Watching presentations • What smart polymers are The statements could be written down or read out: from other students. and what they are used for. • A very long chain hydrocarbon. [Polymer] • Contains a double bond. [Monomer] Auditory: Listening to feedback. • Reactive molecule. [Monomer] • PET. [Polymer] • Ethene. [Monomer] Intrapersonal: Designing an • Plastic. [Polymer] • Joins together to make a plastic. [Monomer] (5 minutes) experiment to test the properties of different materials used for Main packaging of drinks. Teacher Expo Interpersonal: As a group, • Plastics are now often developed for a particular purpose. However, new uses for existing plastics are designing a new coat. being found. • Homework. Design a new • Students need to have some understanding of the vast range in new polymers. Split the class into six groups polymer fit for a particular purpose. and give each a topic: ‘new packaging materials, waterproof coatings for fabrics, dental polymers, wound Students should list its properties dressings, hydrogels, shape memory polymers’. Ask each group to come up with a PowerPoint® and what specific use it is designed presentation (no more than 3 minutes long) about their topic. This should include what their material is, its for. special properties, what it is used for and one fascinating fact. • ICT link-up. This web site This could also have the end product of a poster presentation/ article for a paper detailing the vastness of contains information on smart polymer use in the world today as well as the afore mentioned points. polymers: www.sep.org.uk Pupil development Pupils are using secondary sources to find information on the internet (the library could also be booked and the books used as well). Pupils produce the end product described above. Plenaries Answers – Ask the students to look back at the objectives in the Student Book and answer the questions that have been posed. (10 minutes) This plenary s completed if the end product is NOT the powerpoint but a poster representation of the information. Presentations – Ask the students to deliver their presentations. Have a stopwatch running, and stop the students when they reach their 3 minutes. (15–20 minutes) Learning Outcomes Activities and extensions Most students should be able to: • Students could research into • Give an example of a polymer that is used because of its properties. unusual polymers, e.g. surgical • Give an example of a polymer that has been designed for a specific job. glues. • Ask which synthetic polymers Some students should also be able to: have not been around for more than • Evaluate the suitability of different polymers for particular uses. a hundred years; students could produce a timeline showing the development of important (e.g. Bakelite) or interesting (e.g. superglue) polymers. • Encourage students to research into new biodegradable plastics like the ones used for some plastic shopping bags and babies’ disposable nappies. Ask students to find out the names of the monomer(s) and the polymer and by what action it breaks down, e.g. by the effects of light, bacteria or water. AQA GCSE Science: C1b 4.5 Paper or plastic??? AQA Specification Link Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the social and economic advantages and disadvantages of using products from crude oil as fuels or as raw materials for plastics and other chemicals • to evaluate the social, economic and environmental impacts of the use, disposal and recycling of polymers. Teaching suggestions May be page 194 – 195 in the pupil book to exam how well the pupils have understood the concepts covered. Purple science works questions which link into the degradation of plastics. Also green summary questions. Activities Is packaging needed? – Set up a display of some food already wrapped, e.g. flour, sugar, cereal, then have the same products in plastic containers with scoops. Ask the students how their families usually buy these sorts of foods, and suggest where they can buy the unpackaged food (e.g. markets and ‘shop and save’ type stores). Then ask students to consider the benefits and disadvantages of both. Focus on the advantages of each, e.g. packaged: hygienic, know the brand, know the amount that you are buying, quick to purchase; non- packaged: have as much/little as you want; can easily see the quality. For lower-attaining students this activity could be made into a card sort. This is activity 1 on page 192 in pupils book. Carrier bag survey – Carrier bags are often plastic in the UK. Ask the students to list reasons why plastic is chosen and not paper (as in films from America). Students should recognise that the weather is a large factor. Ask the students to design a questionnaire about the usage of plastic bags. Some question ideas are given in the Student Book. Ask the students to consider what they are going to do with the data, i.e. draw graphs, so they need to ensure that the questions supply quantitative responses. For lower-attaining students, the questionnaire could be supplied from the teacher. Students could then practise asking the questions to other members of staff to gain confidence. The sample size needs to be decided, maybe a few questionnaires completed from each student and the results pooled. The questionnaire could be completed by a street survey. Permission will probably need to be sort from the shop, which is targeted. Also full risk assessment needs to be completed and parental consent with medical forms need to be issued and completed. Alternatively, students could be set the task of asking three people as homework. On returning to school, the data could be pooled in a tally chart and graphs could be drawn either free hand or using Excel. The class could be split into groups and each team could take a different question to report on. The graphs could then be mounted into a display, and each student/group could write their own conclusions from the data collection. Homework Environmental poster – List the factors that affect the number of carrier bags that are used during shopping trips. Then make a poster to make shoppers more aware of the environmental impact of their overuse of plastic bags. Extension Biodegradable plastics – Ask students to find out the ways in which carrier bags, and plastic nappies, are made increasingly environmentally friendly. Learning styles Kinaesthetic: Handling packaged and unpackaged foods. Visual: Viewing the resulting graphs from the carrier bag survey. Auditory: Listening to responses from questions. Interpersonal: Discussing conclusions from results to share with the whole class. Intrapersonal: Evaluating the impact of using plastics on society. ICT link-up There are many pieces of information about biodegradable plastics on the Internet. For example, search the web for ‘biodegradable nappies’. Also search for ‘Biodegradation’ at www.wikipedia.org. AQA GCSE Science: C1b 5.1 How useful is a vegetable?? (1) AQA Specification Link • Some fruits, seeds and nuts are rich in oils that can be extracted. The plant material is crushed and the oil removed by pressing or, in some cases by distillation. Water and other impurities are removed. • Vegetable oils are important foods as they provide a lot of energy. They also provide us with nutrients. • Vegetable oils that are unsaturated contain double carbon carbon bonds. These can be detected by reacting with bromine or iodine. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the effects on using vegetable oils in foods and the impacts on diet and health. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Learning styles • That oils can be extracted Lesson structure Kinaesthetic: Completing a from plants. Starter distillation of plant oil or crushing • That vegetable oils are List – Ask students to make a list of oily foods. Then ask them to consider where the oil comes from, e.g. crisps plant material to extract oil. important foods. – sunflower seeds; chocolate spread – nuts; olive oil – seeds. (10 minutes) Visual: Making a flow chart to • What unsaturated oils are show the different methods for and how we can test for Main extracting plant oils. them. Teacher Expo Auditory: Listening to questions • Some plants quickly release oil when they are crushed, e.g. nuts and seeds. Other oils are more difficult to and responses from other extract and steam distillation needs to be used. students. • Demonstrate steam distillation on a micro-scale or crush plant material to extract oil (be aware of nut allergies, Intrapersonal: Completing eye protection must be worn) using mortar and pestle (see if you get a translucent stain on filter paper). sentences with increasing • Fats are an important part of the human diet. In the media we often hear terms like ‘saturated, unsaturated, scientific information. polyunsaturated fats’. Interpersonal: Working in Give pupils two diagrams – one of an alkane and one of an alkene. Ask them to consider the difference and question and answer pairs. introduce the words saturated – no double bonds, unsaturated – contains double bonds, polyunsaturated – • Homework. Ask students to contains many double bonds. They can then practically classify different fats as saturated or unsaturated using answer the questions posed in the bromine water. learning objectives. Pupil development Pupils carry out experiment to identify whether the oils are saturated or unsaturated and which is the most/least un-saturated. Use cartoon worksheet to help pupils go through the experiment Plenaries Questions and answers – Ask a student to pick a number from 1 to the number of students in the class. Look at which number this corresponds to in the register. Then ask that student to generate a question about the topic studied and choose a person to answer it. The question maker then decides if the answer is correct. If misconceptions are highlighted, then you should take over the question and answer in order to correct them. (10 minutes) Learning Outcomes Practical supportPOINTS Activities and extensions Most students should be able to: Testing for unsaturation • Students could extract oils from • Describe how oils can be extracted from plants. Equipment and materials required petals in order to make their own • Recognise an unsaturated oil. A selection of fats (e.g. butter, margarine, dripping, ‘perfume’. • Describe why plant oils are important in foods. lard, olive oil, vegetable oil), dropping pipettes, test • Students could find the calorific tubes, bromine water (irritant and harmful – see content of a variety of fats that Some students should also be able to: CLEAPSS Hazcard 15), bungs, test-tube rack, water humans eat. They could then • Detail a method for testing unsaturated oils. bath, eye protection. make a bar chart to compare the Details values. An extension of this Students should pipette about 1 ml of each liquid into would be to encourage students to separate test tubes, stored in a rack. If a solid fat is to be look at nutritional labels of tested, e.g. dripping, then it needs to be melted using a different foods, and represent the water bath. About the same amount of bromine water percentage calories from fat in a should be added to each test tube, and each bunged and graphical form. shaken. Ensure that the students wear eye protection and hold the bung and base of the test tube when they shake it. Bromine vapour may be given off (so use pale yellow bromine water), therefore a well-ventilated area is necessary and students should wash their hands after the practical. Asthmatics may experience problems with any bromine vapour present. AQA GCSE Science: C1b 5.2 Naughty but nice!!! AQA Specification Link • Vegetable oils that are unsaturated can be hardened by reacting them with hydrogen in the presence of a nickel catalyst at about 60 °C. The hydrogenated oils have higher melting points so they are solids at room temperature, making them useful as spreads and in cakes and pastries. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the effects on using vegetable oils in foods and the impacts on diet and health. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Special needs. The flow • Reasons why people cook Lesson structure chart could be made as a cut with vegetable oils. Starter and stick activity. Or the flow • What is meant by ‘to Stand-by – Put the key words: ‘saturated’ and ‘unsaturated’ onto two large pieces of paper and pin them at chart could be given in words, harden’ vegetable oils. opposite sides of the room. Read out different examples of chemicals, students should decide whether they are and the students could them • How vegetable oils are saturated or unsaturated and stand by the appropriate sign, e.g. draw a picture for each stage turned into spreads. • Sunflower oil [unsaturated] • Butter [saturated] • Lard [saturated] below the text. • Alkenes [unsaturated] • Alkanes [saturated] (5 minutes) • Learning styles Kinaesthetic: Standing by Main their chosen answer. Teacher Expo Visual: Making a flow chart • When foods are cooked at different temperatures, they have different flavours, appearances, smells and to show the method of nutritional content. Students could compare different potatoes that have been prepared in different ways. hydrogenation of fats. Encourage the students to design their own results’ table to record their observations. Lower attaining students Auditory: Listening to may need to copy a previously prepared one. different questions and • If a room swap can be completed into a home economics suite, then additional experiments can be completed answers. about cooking time. This will help to integrate ‘How Science Works’ into this topic. Encourage students to Interpersonal: Working in contemplate how to make this activity a fair test and list the variables, and identify the dependent and independent groups to make a segment in a variables. news programme. • Students need to know the processes involved in creating a spread from an oil and the reasons why this is done. Intrapersonal: Writing their Split students into small groups and ask them to imagine that they are going to produce a short feature, as part of a own question and answer. TV programme, about how food is manufactured. Give students ideas, e.g. interview a chemical engineer at the oil • Homework. Find out about plant. Students could then make a storyboard to show what would happen in each scene and the information that the risks of a high fat diet. would be given. • Students often struggle with empathy; being able to argue from another viewpoint is a valuable skill particularly in essay writing. Give students different roles: – Chemical engineer. – Lay person. – Science teacher. – Top chef. – Spread company. – Campaigner for health. – Host of the show. Students could then get into character and think about what each person would think about using oils and fats to cook. Then a debate (similar to a talk show) could be chaired. People without specific roles could be the audience and pose questions to the panel. • Students could investigate the degree of saturation in a variety of oils using bromine water. ‘How Science Works’ concepts of fair testing and measurement can be practised. Some might try a colorimeter or a light sensor and data logger to get quantitive data on how much bromine remains after reaction with the oils. A little ethanol will help the oil and aqueous layers to mix for the test. • An Animation, C1b 5.2 ‘Making oils into solid fat’, is available to use on the GCSE Science CD. Plenaries Question loop – Small pieces of paper are given to each student. They write a question and its answer. They then separate the question from the answer and all the papers are collected and shuffled. Each student is then given a question and an answer. The first student reads their question; the student with the correct answer reads their answer, then their question and so on. (10 minutes) Flow chart – Students could summarise the hydrogenation of fats in a flow chart format. Lower attaining students could be encouraged to show this in a diagrammatic format. (5–10 minutes) Learning Outcomes Practical support Activities and Most students should be able to: Investigating cooking extensions • List reasons for why vegetable oils are Equipment and materials required • Give students the nutritional used for cooking. Raw potato cores, boiled potato cores, fried potato cores, mounted needle, magnifying glass. Cooker, information for different • Define the term ‘harden’. chip pan, cooking oil, saucepan, water, stopwatch, knife. potato products. Ask them to • State how oils are turned into spreads. Details draw a graph to compare Ask the students to study the appearance of the three different samples, using the magnifying glass. different cooking techniques Some students should also be able to: They should note the colour and smell. Then using a mounted needle, they can scratch the surface and their fat/calorie contents. • Explain how oils are turned into spreads and comment on the textures. Students should carefully cook the potato cores in cooking oil (this • Ask students to find out the in terms of the bonding and forces between may be completed as a demonstration as boiling oil can be dangerous) and boiling water. They boiling points of different fats molecules. should time how long it takes for each. They could repeat the test three times to gain an average, or used in cooking and to show pool the class results in order to gain more reliable evidence. Once the potatoes have been cooked, this information in an they could be tasted, and students could comment on their different taste and texture in the mouth appropriate diagram, e.g. bar due to the cooking conditions. chart. Safety: Know how to extinguish a fat fire. Comparing oils for degree of saturation Equipment and materials required Iodine solution or bromine water (irritant and harmful – see CLEAPSS Hazcard 15), variety of plant oils, ethanol (highly flammable – no naked flames) test tubes, bungs, dropping pipettes (possibly colorimeter, light sensor, data logging equipment), eye protection. Details Mix the oil and bromine water or iodine solution. Stopper and shake. Judge degree of decolorisation. AQA GCSE Science: C1b 5.3 Emulsions – not just a white wash!!!! AQA Specification Link • Oils do not dissolve in water. They can be used to produce emulsions. Emulsions are thicker than oil or water and have many uses that depend on their special properties. They provide better texture, coating ability and appearance, for example in salad dressings and ice creams. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the effects of using vegetable oils in foods and the impacts on diet and health. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: Lesson structure • Gifted and talented. Students • What emulsions are and Starter could be told that emulsions are how they are made. Prediction – Give each student a bung and a test tube with water and oil in it (about 1ml of each). Ask the part of a group of mixtures called • That emulsions made from students how you could make the oil and water mix. Some might say that it is possible to shake it. ‘colloids’. These students could vegetable oils have many Encourage the class to shake their tubes and make a prediction as to what will happen. Allow the students then be encouraged to define and uses. time to observe. Ask the students what has happened [the oil and water have separated, they are immiscible give examples of other colloids, e.g. liquids (do not mix)]. Ask the students to think of a way of keeping oil and water mixed. Encourage them to sol, gel, foam. think about doing the washing up or clothes washing, i.e. what happens to the fat from plates or on clothes? • Learning styles [Students will hopefully realise that another chemical – an emulsifier – needs to be added to make Kinaesthetic: Students lining up in immiscible liquids mix and make an emulsion.] (10 minutes) order of fat content/making emulsions. Main Visual: Drawing a diagram of the Teacher Expo microscope slide. • Students come into contact with many emulsions in everyday life. One of the most common is milk, which Auditory: Listening to other group is fat suspended in water. Ask the students what type of fat is in milk [animal fat and therefore saturated]. members explain about their food Then encourage the students to make wet slides of different types of milk to see the different emulsions. additives. • Students could record their results in the form of a diagram, but they should also work out the Interpersonal: Working in groups magnification on the microscope (eye lens x object lens). You may need to remind pupils of the correct way to look at and make emulsions. to use a microscope suggest a quick but specific q&a session. Intrapersonal: Making a list of • Students think about another common emulsion – mayonnaise. (If a room swap can be completed into a different emulsions. home economics room, the students could take the mayonnaise home). Ask the students to try to identify the • ICT link-up. Connect a flexi-cam emulsifier in this mixture [egg yolk]. to the head of the microscope. The image of the different milk Pupil development emulsions could then be projected Pupils make wet slides and look at different milk emulsions under the microscope. Pupils draw what they or shown on a TV screen. see in their books – up to you whether it is one magnification or all three for all (or maybe just one slide so • Homework. Ask students to find that pupils can demonstrate the progression of detail when using a microscope). some names/E-numbers of emulsifiers in foods, e.g. soya Plenaries lecithin, E471. Explain – Split the students into groups of three. Give each member a different food additive from ‘emulsifiers, stabilisers and thickeners’. Give the students 2 minutes to find an example of its use and why it is used. Then the students feedback their ideas in their groups. (5 minutes) Learning Outcomes Practical support Activities and extensions Most students should be able to: A closer look at milk • The different types of milk could • Describe what an emulsion is. Equipment and materials required be purchased and the students could • Give an example of an emulsion. Samples of different milks (whole, semi- taste them in a Food Technology skimmed, skimmed) – be aware of lactose- room or outside the laboratory to Some students should also be able to: intolerant students, microscope, slides, see what difference fat makes to the • Explain why emulsifiers are an important addition to some foods. mounted needle, cover slip, dropping pipette. milk (be aware of lactose intolerant • Explain how emulsifiers work in terms of intermolecular forces. Details students). Put a drop of one type of milk in the centre of • If there is access to an ice-cream the microscope slide. Place a cover slip at the machine, then this emulsion could edge, and support it with the mounted needle. also be made. Gently, lower onto the liquid in order to minimise air bubbles. Put the slide onto the microscope stage, and adjust for the lowest magnification and bring into focus. Repeat for other milk samples. (Making mayonnaise Equipment and materials required Two egg yolks (be aware of students with an egg allergy), salt, pepper, oil, vinegar, mustard, bowl, whisk, measuring jug, tablespoon, teaspoon. Details Beat the eggs with a pinch of salt. Add the oil 1–2 teaspoons at a time, while continuing to beat the mixture. After a quarter of the oil has been added, add 1–2 teaspoons of vinegar. Continue to add oil slowly and beat the mixture. Add mustard and pepper to taste. Safety: Wash hands before and after handling eggs. ) only if in food room by request.KEY POINTS AQA GCSE Science: C1b 5.4 Where have the blue smarties gone??? AQA Specification Link • Processed foods may contain additives to improve appearance, taste and shelf-life. These additives must be listed in the ingredients and some permitted additives were given E- numbers. • Chemical analysis can be used to identify additives in food. Artificial colours can be detected and identified by chromatography. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the use, benefits, drawbacks and risks of ingredients and additives in food. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Special needs. An easier way to • The importance of food Lesson structure generate a chromatogram is to give the additives. Starter students a disk of filter paper. Ask them • List the purposes of food Spot the E number – Give the students different food packaging. Ask them to note the E numbers and to use a paintbrush to put a sample of a additives. which families of additives they belong to. Then complete a tally chart to show which additives was food colouring into the centre. Then cut a • How to detect coloured most frequently found in the foods studied. (10 minutes) wick (a wedge shape towards the centre). food additives. Then balance the paper over a beaker Main with water in it. The wick must be Teacher Expo submerged. The colours will then • A lot of people are now very concerned about food additives, but do not realise that many of them are separate into rings. naturally occurring chemicals such as pectin (E440), which is found in fruit. (Pupil dev 1) • Learning styles • Food colourings are often added to food to make them more appealing. Colours can be added to sweets Kinaesthetic: Manipulating information and savoury foods. Students can complete chromatography experiments of different food colourings. cards during the domino game and Then the chromatograms could be stuck into their book and conclusions drawn from their results. making a chromatogram. • Students can evaluate the reliability and validity of the experiment as a means of detecting and Visual: Looking at the chromatograms identifying artificial colourings. (How Science Works opportunity.) and interpreting the information. Auditory: Listening to peers and Pupils development explaining how chromatography works. 1 – Pupil book page 203 – summary question 1 copy and complete the table. Interpersonal: Comparing leaflets with 2 – Carry out the simple chromatography experiment, identifying the colours produce and what colours arguments about food additives and make up the different shades etc. debating the need for food additives. Intrapersonal: Understanding how Plenaries chromatography works. Explain – Ask the students to explain how chromatography works. Then pick three students randomly • Homework. Ask students to choose from the register to read their explanations. Reward the best explanation. (15 minutes) their favourite convenience food (could be a sweet or frozen pizza, etc.). Encourage them to list all the additives in that food, and what they are used for. • ICT link-up. A PhotoPlus, C1b 5.4 ‘Detecting additives’, is available on the GCSE Science CD. Learning Outcomes Practical support Activities and extensions All students should be able to: Detecting dyes in food colourings • Students could investigate the dye in Identify E numbers in a nutrition list (could also do the experiment with Smarties. Different coloured Smarties Carry out a simple experiment to gain a result washable markers to give a greater could be put into dimple dishes. Students range of colours to investigate) wet a paintbrush to remove the dye and Equipment and materials required complete a chromatogram. Most students should be able to: Different food colourings, broken • In recent years, there have been a • Describe why an additive with an E-number might be used and state one example. cocktail sticks, 100ml beaker, ruler, number of food scares involving • Describe one test to show coloured additives. pencil, strips of filter paper that fit into additives, e.g. Sudan 1 dye. Students Carry out the named test and identify the range of colours in the sample provided. the beaker. could look into these using the Internet Details (e.g. search newspaper web sites for ‘food Some students should also be able to: Draw a pencil line 2 cm from the scare’) and newspaper clippings kept in • Explain why a range of different types of food additives are used. bottom of the chromatography paper the school library. They could look at the • Explain how coloured food additives can be detected and identified. when it is in a portrait position. Draw economic and social effect of scares such three pencil crosses on the base line, of as this and the impact on the British food equal distance apart. Dip a clean industry. capillary tube into a food colouring, the colour will suck into the tube. Gently dot one of the crosses, trying to add only a small amount of colouring. Repeat with two further colours. Put a small amount of water in the boiling tube (about 1 cm deep). Lower the chromatography paper into the tube and place in the rack. Leave the chromatogram to develop, until the solvent line is past the last coloured dot. Try not to move the chromatograms while they develop, or they will not be easy to compare. • Students will see which colourings were pure substances and which were mixtures of dyes, and can list the component colours in any mixtures. KEY POINTS AQA GCSE Science: C1b 5.5 How useful is a vegetable??? (2) AQA Specification Link • Vegetable oils are important foods and fuels as they provide a lot of energy. They also provide us with nutrients. • Ethene can be reacted with steam in the presence of a catalyst to produce ethanol. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the advantages and disadvantages of making ethanol from renewable and non-renewable sources. (12.4) • to evaluate the benefits, drawbacks and risks of using vegetable oils to produce fuels. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Special needs. Role-plays could • Vegetable oils can be used as Lesson structure be given to the students to perform fuels. Starter the radio advert/TV advert. The • There are advantages of using List – Ask students to look at the Student Book and list all the fuels detailed that can be used to run a car billboard poster could be half- vegetable oils as fuels. [oil, biodiesel, diesel]. Then ask students to list all the other fuels that they know can be used to power finished and given to the students. • Ethanol can be made from cars [petrol, gas, alcohol, hydrogen]. Organise feedback from the class into two lists on the board. • Learning styles ethene. (10 minutes) Kinaesthetic: Physically sorting the different fuels. Main Visual: Reviewing the billboard Teacher Expo poster. • There is always development in car designs and their engines. Cars were run using petrol for many Auditory: Listening to the prepared years; it has been relatively recently that other fuels have started to be investigated and used in the UK, radio advert. e.g. gas power. Interpersonal: Working in teams to • People are often slow to change, especially when innovations are based on unproven technology. produce marketing material. Therefore car companies will have to make some persuasive advertisements to encourage people to Intrapersonal: Reflecting on what change their cars to run on biodiesel. they have revised and learnt. • Organise students into their preferred learning styles (auditory, kinaesthetic, visual). Ask the visual • ICT link-up. Students could type group to design a billboard poster; the kinaesthetic to make an advert for TV; the auditory group to make up their newspaper article in a a radio advert. All of the marketing material should aim to persuade drivers to convert to biodiesel. publishing or presentation package. (Need to provide pupils with the necessary information in the form of a booklet for them to research The sorting activity could also be their task.) completed using an interactive • Discuss the advantages and disadvantages of using ethene and plant material to manufacture ethanol whiteboard. for use as a fuel. • Homework. Ask students to summarise the advantages of using Plenaries biodiesel compared to petrol. Give AfL (Assessment for Learning) – Each group displays/acts out their marketing material. Question the the students a maximum number of students about any misconceptions in the adverts. Then students vote for the most persuasive advert, that words (40) to encourage them to group could be given a prize. (15 minutes) summarise, rather than regurgitate. Learning Outcomes Activities and extensions Most students should be able to: • Encourage students to find out about other developments in fuels for cars. This • List an example of vegetable oil being used as a fuel. could involve completing an Internet search. • State an advantage of using vegetable oils as fuels. • Students could be played TV adverts about fuel/engine developments, e.g. the • Write the word equation and conditions for the production of ethanol from ethene. Honda campaign 2005 ‘Hate something . . .’, as stimulus material for producing their own marketing material. Some students should also be able to: • Ask students to consider why electric cars are not as environmentally friendly as • Explain the advantages of using vegetable oils as fuels. using biodiesel. Students should have the idea that electricity is a secondary source • Evaluate different fuels in terms of their advantages and disadvantages. and, therefore, pollution is occurring elsewhere to fuel the car. • Write the symbol equation for the reaction of ethene with steam. AQA GCSE Science: C1b 5.6 Vegetable oils AQA Specification Link Students should use their skills, knowledge and understanding of ‘How Science Works’: • to evaluate the effects of using vegetable oils in foods and the impact on diet and health • to evaluate the benefits, drawbacks and risks of using vegetable oils to produce fuels. Teaching suggestions Activities Article – Fats are an important part of our diet. Without them, for example, we would not have any cell walls! Set the students the task of writing an article for a lifestyle magazine. Students should be encouraged to include quotes from fictitious people, e.g. a GP, a dieter etc. They should endeavour to create a balanced article explaining how the body needs fat, but there are effects of having too much fat. Poster – Whenever people go into health centres there are a number of thought provoking health posters on the wall. Try to get some of the posters (e.g. from the school nurse) to show the students. Then set the students the task of designing and making their own poster to highlight vegetable oils in our diet. Homework Alternative fuels – Ask students to complete a storyboard for a segment on a popular car show. The section should be about 5 minutes long and be about biodiesel as a fuel for cars. Extension Presenting – Ask students to act out their storyboard. They may need to go into groups, and choose their favourite from their group, as the storyboard may have more than one character. Bias – There is a lot of bias media about fat in our diet. Split the class into groups. Supply each group with different written materials about fat in our diet, e.g. a leaflet available from the NHS, healthy eating books, lifestyle magazine articles, adverts for low fat foods. Encourage the students to read the articles and list the facts in the work, then to list the incorrect statements. Finally, ask the students to decide if the work was balanced or biased. Fat definitions – In everyday language there are a lot of scientific words used, but people often do not know what they mean. Encourage the students to define all the science words used to define fat (e.g. saturate, unsaturated, cholesterol, trans fats) and the effects on our body if they are eaten in large quantities. They could display this work as a leaflet, poster or a booklet. Learning styles Kinaesthetic: Presenting a segment on a popular car show. Visual: Making a poster for the use in a health centre about fat and diet. Auditory: Discussion about articles that could be biased. Interpersonal: Working as a group to present a segment in a car show. Intrapersonal: Completing definitions about fats. ICT link-up Students could record their presentations using a camcorder. Then using a firewire card, the data could be manipulated and images/text added using Windows Movie Maker. The video could then be used on the school web site, or shown at a ‘New Parents Evening’ or in an assembly. A PhotoPlus is available for C1b 5.6 on the GCSE Science CD. AQA GCSE Science: C1b 6.1 How active is our world??? ( Making you aware – have combined lesson 1 and 2 because I don’t feel 1 had enough substance to warrant doing it separately) (in the numbering there will be NO C1b6.2) AQA Specification Link • The Earth consists of a core, mantle and crust. • Scientists once thought that the features of the Earth’s surface were the result of the shrinking of the crust as the Earth cooled down following its formation. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Learning styles • The basic structure of the Lesson structure Visual: Labelling a diagram of the Earth. Starter Earth’s structure. • What tectonic plates are. Have an unlabelled diagram of the structure of the earth on the board and pupils are instructed to copy the Interpersonal: Listening and • Why tectonic plates move. diagram and use pupil book page 210-211 to complete any labels that they feel necessary (minimum of what interacting with other students crust mantle inner core and outer core – vary level of detail according to group ability.) during a discussion. Intrapersonal: Creating questions to Main the answers that have been Teacher Expo supplied. (See Plenaries.) Show the animation on www.brainpop.com on continents and how they are formed. • ICT link-up. An image of the This gives information on the super continent pangea and how the plates have moved Earth can be placed into interactive Show pupils the demonstration of convection currents using potassium manganate (e.g. beaker, potassium whiteboard software and labelled. manganate(VII), convection current, Bunsen burner) . Then ask students to relate this to the Earth (PD1) The labels can be covered with ICT opportunity: boxes and used as a class quiz Students need to know what happens at plate boundaries and the effects of natural disasters. This topic is exercise. excellent to show visual images of plate boundaries, and the students are often very enthralled by it. Split the ICT link-up. The Internet could be class into three groups: one group researches volcanoes, another earthquakes and the third looks at used to show news reports and prediction and prevention. videos of earthquakes, volcanoes Plate boundary worksheet – talk through with pupils what they think will happen from the pictures, then and tsunamis. Students’ work could direct them to the textbook be scanned and displayed on the To gather more/the correct information.(PD2) school web site. Pupil development www.volcano.und.nodak.edu. PD1 - Worksheet on the plate boundaries – pupils stick in their books and explain how these plates move PD2 - Pupils use the worksheet of the three things that happen at plate boundaries as a starting point and • Homework. Find out how old they add information (from Nelson old) to illustrate what is happening and why. scientists believe the Earth to be http://www.uwgb.edu/dutchs/EarthSC202Notes/quakes.htm good web page to show different plate [about 4 600 000 000 years old]. boundaries and animations of how they interact. Plenaries Definitions – Ask students to define the key terms used in the lesson e.g. plate, plate tectonics, Pangaea, convection currents. (5 minutes) Learning Outcomes Practical support Activities and extensions All students should be able to : KE Convection currents • Ask the students to think of Label a simple diagram of a cross section of the earth. Equipment and materials required questions or arguments that Potassium manganate crystals (oxidising Wegener could have been facing Most pupils should be able to: agent and harmful), tweezers, large glass from the scientific community. A State that the outer layer of the earth is made up of tectonic plates. beaker, cold water, Bunsen burner and safety volunteer or group of volunteers State why these plate move. equipment, tripod and gauze, eye protection. could pretend to be Wegener, then List what happens at the plate boundaries. Details other students could pose their Fill the beaker about 75% with cold water questions/arguments for Wegener and put onto a tripod. With a set of tweezers, and his team to answer. Some pupils should be able to: add no more than three crystals to the bottom Explain how convection currents cause the plates to move. of the beaker. Put the Bunsen burner under Explain why earthquakes and volcanic activity is so difficult to predict. the beaker at the point where the crystal is and heat on the blue flame. The convection current should become visible. Safety: Potassium manganate(VII) – see CLEAPSS Hazcard 56. Handle carefully as crystals will stain hands and clothing. Y Worksheet!!!! POINTS AQA GCSE Science: C1b 6.3 Everybody lets off gas in some form!!! AQA Specification Link • During the first billion years of the Earth’s existence there was intense volcanic activity. The activity released the gases that formed the early atmosphere and water vapour that condensed to form the oceans. • Some theories suggest that during this period the Earth’s atmosphere was mainly carbon dioxide and there would have been little or no oxygen gas (like the atmosphere of Mars and Venus today). There may also have been water vapour, and small proportions of methane and ammonia. • Plants produced the oxygen that is now in the atmosphere. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to explain and evaluate theories of the changes that have occurred and are occurring in the Earth‘s atmosphere. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Special needs. Images and text to • What the Earth’s Lesson structure explain the five stages of atmosphere was like in the Starter development of the Earth’s past. Grouping gases – Ask students to list as many gases as they can think of. Then on the board put three titles: atmosphere could be given to the • How the mixture of gases in ‘element, compound and mixture’. Then encourage each student to go to the board and add a gas from their students. They could then cut and the Earth’s atmosphere was list under the correct column heading. Look at the board, and if there are any incorrect answers, say to the stick them into the appropriate produced. class there are ‘x’ number of mistakes. Then ask the students to see if they can pick out the mistakes. cartoon strip boxes. • How oxygen was released (10 minutes) • Learning styles into the Earth’s atmosphere. Kinaesthetic: Ordering the Main statements from the specification. Elicit from pupils the levels of gases in the atmosphere today. Visual: Creating a cartoon strip to Nitrogen – 78% carbon dioxide – 0.04% show atmospheric development. Oxygen – 20% Other gases – 2% Auditory: Listening to other students’ sketches. Tell pupils the percentage of gases at the start of the process. Interpersonal: Working in a group to create a sketch. Intrapersonal: Making a personal Ask pupils for ideas how the atmosphere might have changed over the years. list of gases. Direct pupils to the major changes in gas quantities and what events might have • Homework. Find some examples changed them – e.g. photosynthesis and respiration (remind pupils of the equations here of organisms that probably to help with the thought process). What do we need to survive? Etc. produced the first oxygen. Students Pupil development. could be encouraged to find images, • Give students a cartoon strip with five frames, with space to draw a picture and write notes. Encourage not just names. students to use a textbook to detail five stages in the development of the atmosphere. They should draw an image and write text to explain the atmosphere’s composition and how it compares to other planets in our current solar system. Plenaries Pupil could predict what the earth will be like in five hundred years time. Give pupils some information about the carbon emissions etc. they could also write a paragraph about the effect of these gases on life as we know it.. • ICT link-up. A background for each part of the atmosphere’s development could be made for the students if a data projector is available. Get images of the different stages from the Internet and put one per page in PowerPoint, then project behind the students while they perform their sketch. Learning Outcomes Activities and extensions Most students should be able to: • Students could display the composition of the Earth’s atmosphere at different stages • Name the gases that probably made up the Earth’s early atmosphere. in the form of charts and graphs. • List the major events that formed today’s atmosphere. • Students could contrast the Earth’s atmospheric development with that of other • State how oxygen entered the Earth’s atmosphere. planets. Venus would be a good example, as some scientists believe that it has had a runaway greenhouse effect that has caused its current atmosphere. (This links to the Some students should also be able to: greenhouse effect, featured previously in C1a.) • Explain how the Earth and its atmosphere was formed. • A PhotoPLUS, C1b 6.3 ‘The atmosphere’, is available on the GCSE Science CD for individuals, groups or the whole class to use. AQA GCSE Science: C1b 6.4 The carbon cycle AQA Specification Link • Most of the carbon from the carbon dioxide in the air gradually becomes locked up in the sedimentary rocks as carbonates and fossil fuels. • Nowadays the release of carbon dioxide by burning of fossil fuels increases the level of carbon dioxide in the atmosphere. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to explain and evaluate theories of the changes that have occurred and are occurring in the Earth’s atmosphere • to explain and evaluate the effects of human activities on the atmosphere. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Special needs. Key words could • Carbon moves in and out of Lesson structure be supplied on the board to help the atmosphere. Starter students label the carbon cycle. • The amount of carbon Recap with pupils the reason why the levels of carbon dioxide changed over the years (photosynthesis and Alternatively, the exercise could be dioxide is increasing in the respiration) and the importance of this in our lives. turned into a cut and stick activity. atmosphere. Show pupils the model of carbon dioxide – you make it using the model kit. • Learning styles Kinaesthetic: Completing a range of Main experiments to find out the •Guide through practical of making and testing carbon dioxide. properties of carbon dioxide. 1. to make carbon dioxide gas, react hydrochloric acid (1M) with marble chips in a conical flask Visual: Labelling the carbon cycle. 2. Set up collection of gas through delivery tube into 6 test tubes – with bungs to stopper once collected. Auditory: Listening to statements 3. test the test tubes as per worksheet instructuctions. from other students about the Lesson is concentrating on their Sc1 skills as much as the science behind it. Get pupils to measure out and carbon cycle. Interpersonal: weigh the acid and the marble chips. (40ml of acid, g marble chips.) Working as a class to make a carbon cycle model. Intrapersonal: Pupil development. Appreciating the mechanism of Pupils carry out the practical collecting and testing their gas. Pupils fill in their results on the worksheet. carbon recycling on Earth. • Homework. Plenaries Pupils complete the explanation Go through some of the ideas on the question sheet relating to the practical – pupils to finish the sheet for sheets from the lessons practical homework to check underdstanding. • ICT link-up. The semi-finished diagram of the carbon cycle could be projected using a data projector. Alternatively, the diagram could be put into specialist interactive whiteboard software with the labels at the bottom of the screen. Students can then drag the labels to the appropriate positions on the diagram. Learning Outcomes Practical support Most students should be able to: The properties of carbon dioxide • Describe the main parts of the carbon cycle. Equipment and materials required • State that burning fossil fuels increases the amount of carbon dioxide in the atmosphere. Lime water (irritant), straws, test tube, carbon dioxide filled balloon, bucket of water, sealed test tubes of carbon dioxide gas, Bunsen burner and safety equipment, splints, Some students should also be able to: universal indicator solution, water, eye protection. • Explain why there is a general trend that the amount of carbon dioxide in the air is Details increasing. Set up five stations each with a separate activity card to explain to students what to do. Students must wear eye protection. Station 1: Students should blow gently through the straw into lime water and note their observations. Ask the students to explain the chemical reaction that is occurring (link back to the limestone cycle in C1a). Station 2: Students should investigate the density of carbon dioxide. They should release the balloon in air (it will sink – more dense) and into water (float – less dense). Station 3: Light a splint and put it into a test tube of carbon dioxide and observe. Station 4: Students should blow through a straw into a test tube of diluted universal indicator solution and observe the colour change. Eye protection must be worn. K AQA GCSE Science: C1b 6.5 carbon cycle. AQA Specification Link Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Special needs.. • The main gases in the Lesson structure • Learning styles current atmosphere. Starter • Homework. • The percentage composition Recap with pupils the amounts of gases in the atmosphere. Draw a pie chart (some form of representation) of the current atmosphere. of how of each gas was present first and how it has now changed. • ICT link-up. • About noble gases and their uses. Main Introduction of the carbon cycle. The carbon cycle is a network of reactions that add or remove carbon dioxide into the atmosphere. Remind pupils of the ones talked about already – photosynthesis and respiration. 1. (Role play/get up activity) Using laminated cards on string pupils construct the carbon cycle/ the network of reactions. Yellow joined by string, the blue stand by their process. discuss the parts of the cycle that humans are changing and how it all interacts 2. Visual activity – using other laminated cards construct the cycle on t he board and pupils display this on A4 paper with additional information found in the books. Plenaries Learning Outcomes Activities and extensions AQA GCSE Science: C1b 6.6 Gases in the atmosphere AQA Specification Link For 200 million years the properties of different gases in the atmosphere have been much the same as they are today: – About four-fifths (80%) nitrogen – About one-fifth (20%) oxygen – Small proportions of various other gases, including carbon dioxide, water vapour and noble gases. • The noble gases are in Group 0 of the periodic table. They are all chemically unreactive gases and are used in filament lamps and electric discharge tubes. Helium is much less dense than air and is used in balloons. Students should use their skills, knowledge and understanding of ‘How Science Works’: • to explain and evaluate theories of the changes that have occurred and are occurring in the Earth’s atmosphere. Learning Objectives Teaching / Learning activities (including How Science Works) Teaching suggestions Students should learn: • Special needs. The class could • The main gases in the Lesson structure write the story about the changing current atmosphere. Starter Earth’s atmosphere together and the • The percentage composition Pie chart – Ask the students to find the percentage of each gas in the current atmosphere. Encourage the learning support assistant could act of the current atmosphere. students to represent this information as a pie chart. (15 minutes) as scribe using the board. • About noble gases and their Code breaker – Ask students to decipher the following code: Alternatively, the story could be uses. 1, 9, 18, 9, 19, 1, 13, 9, 24, 20, 21, 18, 5, 15, 6, 7, 1, 19, 5, 19 written into discrete sentences and The key to the code is that each letter is represented by its position in the alphabet, e.g. A_1, Z_26. [Air is a the students could order them and mixture of gases.] (10 minutes) stick them into their book. Reflection – Give the students an A4 sheet of paper and ask them to make three columns. The first should be • Learning styles headed with ‘what I already know’, then ‘what I want to know’ and finally ‘what I know now’. Ask the Visual: Creating a spider diagram. students to consider the title of the double page spread and complete the first two columns with bullet points Auditory: Listening to other of information. (10 minutes) students explaining their key term. Interpersonal: Working as a group Main on a story. • Students may not know what a noble gas ‘looks’ like. Get four gas jars, and seal them with tape. Label Intrapersonal: Breaking the code to them as the first four noble gases. Put these out onto the tables and ask the students to describe their reveal the mystery sentence. chemical. • Homework. Ask students to find • Then bring in a helium balloon and ask the students what it contains, and list reasons why the gas is out what scientists predict will suitable for filling balloons [less dense than air, cheap, inert]. happen to the composition of the • Then show students a filament bulb and ask them to think about what is inside it and why it is fit for that Earth’s atmosphere. It is important purpose [stops the tungsten reacting with oxygen when it gets hot]. Students could then complete a spider that the students list their sources. diagram to explain what noble gases are, their uses and properties. Then next lesson the information • The percentage composition of gases in the Earth’s atmosphere has changed over time, but has remained can be compared and consider relatively static in the last 200 million years. Ask students to imagine that they are Earth and to write a whether bias has crept into the creative story about how its ‘clothes’, i.e. atmosphere, has changed and why. Students could be encouraged evidence gathered. (This relates to to share ideas and storyboards to create a group story. ‘How Science Works’ – societal aspects.) • Alternatively, the class could be split into three. One group writes the beginning of the story, another the • ICT link-up. Students could middle and the final one writes the end. In order to complete this last suggestion, a link sentence from each draw their pie chart using Excel. section needs to be provided to the groups so they know where/how to start and/or finish their part of the story. Plenaries Guess what – Ask the students to break off into pairs. Give each pair a pack of cards with separate key words per card, e.g. oxygen, nitrogen, air, gas, carbon dioxide, photosynthesis, methane, ammonia, Earth, noble gas, helium, argon. The students should take it in turns to pick a card and look at the key term. They should explain it to their partner without using the key word and the other student should guess the word. Play one pair against another. The pair with the most correct guesses in a set time wins! (5–10 minutes) Reflection part 2 – Ask the students to return to their A4 table. Ask them to add information to the last column, ‘what I now know’, that isn’t included in the middle column. They should also correct any misconceptions from the middle column and ask for help if they have not found out some information that they wanted. (10 minutes) Learning Outcomes Activities and extensions Most students should be able to: • Encourage students to think about other examples of noble gases and their • List the main gases in the atmosphere and the approximate percentage composition of the uses e.g. Kr for lasers. atmosphere. • Students could compare the fractional distillation of crude oil to the • List the noble gases and state some uses. fractional distillation of liquid air. A video of this process is available from Industrial Chemistry (RSC). Some students should also be able to: • Explain how ammonia and methane were probably removed from the Earth’s atmosphere. • Give examples of noble gases and explain some specific uses. AQA GCSE Science: C1b 6.7 Earth Issues AQA Specification Link Students should use their skills, knowledge and understanding of ‘How Science Works’: • to explain why scientists cannot accurately predict when earthquakes and volcanic eruptions will occur • to explain and evaluate the effects of human activities on the atmosphere. Teaching suggestions Activities Earthquakes news report – Show the students footage of an earthquake, maybe the 2004 Boxing Day tsunami (search for ‘tsunami video’). Ask the students to imagine that they are a reporter for a news show. They are to imagine that there is an earthquake – anywhere in the world of their choice (encourage them to pick a place near a plate boundary). Then they should prepare a news report – live from the scene of the earthquake. Students could then present their news reports to the class. Their reports should include the difficulty in predicting earthquakes. The Carbon Problem Diary – Ask students to look at the different characters in the Student Book and read their speech bubbles. Students should try to get into character and write a diary for a short period of time. Then ask the students to review the diary and underline the parts that require fossil fuels to be burned. The students could write a personal recommendation to the character about how to reduce their carbon emissions. Homework Kyoto – Ask students to find out what the Kyoto agreement is. They could also find out about how the UK has met/tried to meet this agreement and contrast this with the reluctance from the USA. Research could include subsequent meetings, e.g. Montreal 2005, and any progress made. Extension Flip-book – Students could create separate frames of an earthquake from the focus, showing the p and s waves as they extend from the focus. Then fix the frames together with a binding on the left-hand side. Then students flip the books and get a moving image of the waves from the focus of an earthquake. Map – Give the students a map of the world and ask them to chart the plate boundaries. Then give them data for the occurrence of large earthquakes and volcanoes in the last few years. Students should then add a key, and plot the positions of the natural disasters in order to see a pattern. Learning styles Kinaesthetic: Acting out their news report. Visual: Completing a map to chart earthquakes and volcanoes. Auditory: Listening to students’ news reports. Interpersonal: Discussing earthquakes – difficulty in predicting them and the consequences of earthquakes. Special needs Each student could be given a diagram to form a flick book of a natural disaster and colour it. Then the class could put them into order and make the flick book.
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