Biology Spec points covered Starter Practical activity Teacher-led activity CB2a Mitosis B2.1 B2.2 B2.3 B2.4 Describe mitosis as part of the cell cycle including the stages interphase, prophase, metaphase, anaphase and telophase and cytokinesis Describe the importance of mitosis in growth, repair and asexual reproduction Describe the division of a cell by mitosis as the production of two daughter cells, each with identical sets of chromosomes in the nucleus to the parent cell, and that this results in the formation of two genetically identical diploid body cells Describe cancer as the result of changes in cells that lead to uncontrolled cell division Ask students to identify what is needed for humans to grow, and establish the idea that new cells are important. Then ask students to identify the point where growth stops. Challenge them to say whether cell division to produce new cells therefore stops at this point as well. Elicit the idea that although adults do not grow in height, they still need to produce new cells. Tell students that new body cells are produced by a form of cell division, which we call mitosis. Use a light microscope to look at mitosis in plant cells. Root tip squashes are prepared as part of the practical. Students should be able to identify the different stages of the cell cycle from the prepared slides or the slides they have prepared themselves. Equipment: If preparing own slides: garlic clove with roots, distilled water, paper towel, microscope slides and coverslips, watch glass or small dish, microscope with x 100 and x400 magnifications, fine forceps, pencil with rubber end, hollow glass block with few drops of hydrochloric acid, toluidine blue stain in dropping bottle, soft tissue, beaker of tap water, eye protection If using pre prepared slides: prepared and labelled slides of each phase of mitosis, microscopes with x100 and x400 magnifications Optional: digital microscope Model mitosis using clothes pegs with the spring removed from the middle. To help describe the duplication of chromosomes during cell division, show students the clothes peg. From one side it will look like a chromosome’, but turned to the wider side it will look like two chromatids, which can then be divided up into two separate chromosomes. Digital resource: Mitosis video
CB2b Growth B2.5 B2.7 B2.6 Describe growth in organisms, including: (a) cell division and differentiation in animals … Demonstrate an understanding of the use of percentiles charts to monitor growth Explain the importance of cell differentiation in the development of specialised cells Students should work in small groups to list as many examples as they can remember of different kinds of cell in the human body. They should then add any details they remember about the cells, such as where they are found, what they do, and what is special about them Students use a microscope to look at prepared slides of specialised human cells. Display on the board a list of the specialised cells on the slides, but not in the order that the slides are labelled. You may need to indicate where to look for some of these in the tissues, for example ciliated and other epithelial cells line the edge of a tissue. Adaptations of cells in slides suggested: red blood cells are red because they contain haemoglobin that combines with oxygen for transport around the body; muscle cells contain proteins in the cytoplasm that allow the cell to contract; neurones have a long fibre that carries electrical signals around the body; fat cells store large amounts of fat in droplets in the cytoplasm; a sperm cell has a tail that helps it move through the female reproductive system to reach the egg for fertilisation; an egg cell has a large amount of food in the cytoplasm to provide Show students a block of steel, or some steel car parts such as screws, and a car (or image if not available). Suggest that the objects could be used to model unspecialised and specialised cells, by using the steel to represent an unspecialised cell, while the steel car parts represent 'specialised' cells. Digital resource: Specialised cells video Discuss a percentile growth chart and how a data set is split into percentiles. Digital resource: Interpreting growth curves presentation
ask what causes the plants to look different. Explain that the variation we see is due to different types and arrangements of cells in each type of plant. on the constancy of conditions in which the seedlings are kept. If they vary, discuss with students possible reasons for this. Equipment: Tray of at least 40 seedlings (fast growing, e.g. mustard, cress or brassica) grown on a damp absorbent surface such as paper towel or capillary matting, blunt forceps, balance accurate to 0.01 g, beaker of tap water for rinsing seedlings, sheet of paper towel, petri dish base or lid or other shallow container, water for watering seedlings. tip, point out the following features: root cap meristem zone of elongation zone of differentiation: Note that the cells begin to look different in terms of size across the root, as cells in some areas elongate faster than others. However, true differentiation occurs when cells develop special features that are related to particular functions. Ask the students questions as appropriate, such as: what do the cells look like in the meristem, and why are they like that? what causes the root to get longer? which kinds of specialised cells are
SDICN) tablet in 100 cm3 distilled water. Sterile bottles (e.g. Diluvials), microwave oven, heatproof glass jugs or 1 dm3 glass beakers, plastic film, stirrers, fume cupboard (if available), 0.1 M potassium hydroxide, pH meter, accurate balance, pipettes, fridge for storing vials, cauliflower ‘head’ broken into florets For students: forceps in beaker of sterilising solution (SDICN), 70% ethanol, paper towel, small piece of cauliflower (‘floret’), scalpel, screw-lid jar of sterilising solution (SDICN), empty beaker (for collecting waste), tube with lid (e.g. Diluvial) containing growth medium, clean tile, marker pen, access to light bank or well-lit window different colours below the top bead. Explain that these new, slightly specialised cells are also stem cells because they are able to produce a range of specialised cells, but they are each only able to produce a particular range of types. These slightly specialised cells also divide to produce more identical cells, or cells that develop into even more specialised cells. Continue the diagram for another level or two. Ideally, use a graduation in tint for each ‘cell line’. Point out the beads in the bottom row and explain that these are fully specialised body cells, which are unable to produce any other type of cell. Digital: Stem cells video
B2.14 sheath and the role of neurotransmitters Explain the structure and function of a reflex arc including sensory, relay and motor neurones the person in the clip considered it important to appear on TV/in a video and what the nature of his/her accident was. Elicit the idea that the spinal cord has been damaged, preventing impulses from sense organs below the neck reaching the brain and also preventing impulses from the brain reaching the parts of the body below the neck. Students are likely to calculate speeds of about 10 m/s. This is somewhat slower than the speed at which an impulse is actually transmitted along a neurone because the investigation involves many other factors (including synapses, brain processing and students’ reaction times), which slow the process down. In the body there are a range of different types of neurones, which will transmit impulses at different speeds, usually between 20–100 m/s. Equipment: stopwatch, tape measure the lights are turned back on. Ask a student to kneel on a chair, with his/her ankles hanging down loosely. Gently tap the Achilles tendon at the back of the ankle and the foot should swing outwards. Ask a student to sit with his/her legs crossed so that one leg hangs freely. Gently tap under the knee cap with the side of your hand to see the knee jerk reflex action (or patellar reflex). You can point out that the ankle and knee jerk reflexes are part of a system that detects slight variations in position and causes muscles to relax and contract accordingly, helping you to stand. Digital: Reflex arc
interactive CB3a Meiosis B3.3 B3.5 Explain the role of meiotic cell division, including the production of four daughter cells, each with half the number of chromosomes, and that this results in the formation of genetically different haploid gametes The stages of meiosis are not required Describe the genome as the entire DNA of an organism and a gene as a section of a DNA molecule that codes for a specific protein Write the following words on the board: cell, chromosome, DNA, gene, nucleus. Challenge students to work in groups to produce a labeled drawing to show the relative positions of these features. Ask students for ideas on what the term ‘genome’ means and establish that this describes all the DNA in an organism. Students should produce a poster showing the main events that take place during meiosis. Use dark and pale socks to allow you to model the behaviour of ‘sets’ of chromosomes with dark colours being one set and pale colours being the other. String can be used to model the nuclear and cell surface membranes. Digital: Meiosis animation CB3b DNA B3.4 B3.6 Describe DNA as a polymer made up of a two strands coiled to form a double helix b strands linked by a series of complementary base pairs joined together by weak hydrogen bonds Investigate how to extract DNA from fruit Show students a clip from the news or a detective/crime programme with Schene of Crime Officers at work. Ask students what is going on and what sort of evidence is being looked for. You should get the answer ‘DNA’ amongst others – if not, make the Student extract DNA from peas. Students should be able to obtain a white layer of DNA in their tubes. Equipment: 100 cm3 measuring cylinder; two 250 cm3 beakers; 100 cm3 beaker; granular sodium chloride; frozen peas Ensure that students understand that the term ‘complementary’ means ‘fitting together’ (rather than ‘matching’). Illustrate this by using jigsaw pieces, Lego® or pieces of quick-fit lab apparatus to show that parts fit together when
B3.16 Calculate and analyse outcomes (using probabilities, ratios and percentages) from monohybrid crosses and pedigree analysis for dominant and recessive traits controls whether we are male or female. Males have XY and females have XX. Ask students to draw a genetic diagram to explain why about 50% of the UK population is male and about 50% of the population is female. Go through the answer on the board. then shade in the symbols to match the key. come to give a talk to the class. Can people be tested for the allele? Why would they want to be tested? What should they do/not do if they are carriers? What are the options for couples who are both carriers but wish to have children? Alternatively use video supplied. Digital: Cystic fibrosis video CB3e Gene mutations B3.19 B3.20 State that most phenotypic features are the result of multiple genes rather than single gene inheritance Describe the causes of variation that influence phenotype, including a genetic variation – different characteristics as a result of mutation and sexual reproduction Give students a few minutes to design a cat that has a few obviously mutant features. Then challenge them to write down the story of how the cat got its mutant features. (e.g. ionising ray or mutating substance), encourage them to think about what effect this must have on Students use a simple eye colour scale to collect data on the variation in eye colour in the class or other groups (e.g. families). Students will need to decide on a question to answer using the data they will collect, and then decide on who they need to collect data from to answer that question. Discuss the Human Genome Project and how evidence from genomes is now used to predict the risk of developing diseases that are affected by different alleles and whether a person may respond poorly to certain drugs.
B3.21 B3.22 B3.23 Discuss the outcomes of the Human Genome Project and its potential applications within medicine State that there is usually extensive genetic variation within a population of a species and that these arise through mutations State that most genetic mutations have no effect on the phenotype, some mutations have a small effect on the phenotype and, rarely, a single mutation will significantly affect the phenotype the cat's body to result in the changed characteristic. Explain how mutations are really caused by mistakes in DNA, and that this changes the allele of a gene, and so the form of the characteristic that the gene produces. Students create a tally chart and draw a frequency diagram. Eye colour is an inheritable feature (as a result of several genes), so there should be evidence of this in the results. Equipment: Images from the internet to identify the following main iris colours: blue, grey, green, light brown/amber, brown. Label the images with their colours. Additional features in the iris may be seen in different colours, e.g. spots or rings of brown or yellow, and so may need additional images if these are being recorded. Digital Genetic variation in plants video CB3f Variation B3.20 Describe the causes of variation that influence phenotype, including a genetic variation – different characteristics as a result of mutation and sexual reproduction Ask students to work in pairs and to note down six examples of variation in human characteristics. For each example, they should identify how they vary (can the variations be grouped, as in eye This practical provides an opportunity to consider genetic and environmental variation within one set of characteristics, the shape and form of leaves. Write up a list of characteristics on the board, then draw a Venn diagram on the board of two intersecting circles. Add at least one characteristic to each
C1.14 C0.1 properties of these elements and their compounds Describe how Mendeleev used his table to predict the existence and properties of some elements not then discovered Recall the formulae of elements, simple compounds and ions unshaded, one half shaded, and one completely shaded. Ask the students to sort the shapes into groups. There are different ways in which these could be sorted including number of sides and amount of shading. The exercise is intended to encourage students to think about how similar items may be sorted according to different properties. Students should produce three columns or rows in the order Li, Na, K; Mg, Ca, Sr; F, Cl, Br (or Li, –, K; Mg, –, Sr; F, –, Br, I). nearby elements in the same group. Cut a piece of lithium and then potassium on a tile, describing the ease of cutting as you do this. Ask the students to predict what will be observed when attempting to cut sodium, then cut a piece of sodium and describe the ease of cutting. Lithium is the hardest and potassium is the softest. Show sealed samples of chlorine and iodine. Emphasise how, at room temperature, chlorine is a gas and iodine is a solid. Ask the students to predict the state of bromine, then show a sealed sample of bromine. This is liquid at room temperature and vapour may also be present.
Equipment: Eye protection, gloves. Lithium, sodium, potassium. In small sealed containers, samples of chlorine, bromine (a few drops) and iodine (a few crystals). Tile, forceps, scalpel or small knife. Digital Mendeleev’s Periodic Table presentation CC4b Atomic number and the Period Table C1.15 C1.16 Explain that Mendeleev thought he had arranged elements in order of increasing relative atomic mass but this was not always true because of the relative abundance of isotopes of some pairs of elements in the periodic table Explain the meaning of atomic number of an element in terms of position in the periodic table and number of protons in the nucleus Write some key words to do with atomic structure on the board, e.g. atom, proton, neutron, electron, nucleus, shell. Students work individually or in pairs to write definitions for these words. Students carry out a practical in which they investigate some physical properties of metals and non-metals. They test various solids (aluminium, copper, sulfur, carbon) for their electrical conductivity, malleability, appearance and density. Equipment: eye protection; battery, bulb, wires with crocodile clips; small hammer; heat-resistant mat or wooden board; paper towels; 50 cm3 measuring cylinder; ±0.1 g Work through with students: the recall of some chemical symbols for elements; how Mendeleev organised the elements into a table; Mendeleev’s use of his tables to make predictions about elements not yet discovered. The focus of the lesson may depend upon the prior knowledge and understanding demonstrated by the
C1.17 C1.18 Describe that in the periodic table a elements are arranged in order of increasing atomic number, in rows called periods b elements with similar properties are placed in the same vertical columns called groups Identify elements as metals or non-metals according to their position in the periodic table balance; aluminium, copper, sulfur, carbon (graphite and charcoal) – sized to fit in the measuring cylinder. students in the Starter activity. Digital Element discovery presentation CC4c Electronic configurations and the Period Table C1.19 C1.20 Predict the electronic configurations of the first 20 elements in the periodic table as diagrams and in the form, for example, 2.8.1 Explain how the electronic configuration of an element is related to its position in the periodic table Draw diagrams to show the electronic configurations for sodium and oxygen, and write their configurations as 2.8.1 and 2.6. Challenge students to spot the links between these models: the number of numbers in a written configuration is equal to the number of circles drawn; each individual number represents the number of dots or crosses on a circle; the numbers are Students produce their own element sheets by: writing electronic configuration, name and atomic number on one side drawing the electronic configuration diagram and atomic number on the other side. Allocate each student one element from H to Ca (there may be duplicates). Students organise the sheets on the floor into atomic number order (as in the periodic table). Outside, chalk four circles on the ground to represent shells. Each student represents electrons (the teacher or a student could represent the nucleus). Starting with the inner circle, the students occupy each circle following rules for electronic configurations. Extra students in a large class may be used to call out or record the identities
shown in order (from inner circle to outer circle). When complete and checked, discuss the links between position, atomic number and electronic configuration. When the sheets are turned over it should reveal: period number = number of shells group number = number of electrons in outer shell (except for group 0, which is full) sum of numbers = atomic number. Equipment: A4 or A3 (better) paper of the elements formed and/or to capture the activity using Digital Electrons and groups presentation CC5a Ionic bonds C1.21 C1.22 C1.23 Explain how ionic bonds are formed by the transfer of electrons between atoms to produce cations and anions, including the use of dot and cross diagrams Recall that an ion is an atom or group of atoms with a positive or negative charge Teacher demonstrates that show energy is released when certain metal + non-metal compounds are formed. For example, magnesium + oxygen, iron wool + oxygen, sodium + chlorine and copper foil + chlorine. Students complete target diagrams for different elements, state the number of electrons lost or gained to form an ion and add atom and ion symbols. They are then asked to organise the cards in the same way as the elements are arranged in the periodic table. Start with the idea that atoms form bonds to become more stable, like the noble gases. Then explain the formation of ions and ionic bonds, linking the ion formed with the periodic table and using dot and cross diagrams to illustrate what
C5b Ionic lattices C1.25 C0.1 C1.26 C1.27 Explain the use of the endings –ide and –ate in the names of compounds Recall the formulae of elements, simple compounds and ions Deduce the formulae of ionic compounds (including oxides, hydroxides, halides, nitrates, carbonates and sulfates) given the formulae of the constituent ions Explain the structure of an ionic compound as a lattice structure a consisting of a regular arrangement of ions b held together by strong electrostatic forces (ionic bonds) between oppositely-charged ions Ask students to explain this (very) old chemistry joke: A sodium atom bumped into a chlorine atom in the street. When they picked themselves up the sodium atom looked distressed. The chlorine atom said, “what’s wrong?” “I’ve lost an electron,” said the sodium atom. The chlorine atom said “are you sure?” “Yes.” said the sodium atom, “I’m positive.” Students use information about ionic bonds, ion size and electrostatic forces to make and evaluate a model of the ion structure in sodium chloride. Students use polystyrene balls (or similar) and cocktail sticks to make a model of the ionic lattice formed by sodium chloride. When evaluating their models, students should note good and bad points. Students should form a 3 3 cubic lattice with alternate Na+ and Cl- ions. Equipment: per group: 13 small polystyrene balls labelled (Na+ - sodium ions) 14 large polystyrene balls (Cl- - chloride ions) and 60 cocktail sticks. (The chloride ions should be roughly twice the size of the sodium ions) Explain ionic lattice structures; what they look like, how they are formed and how they influence the crystal structure of ionic solids. Demonstrate how ionic formulae can be worked out using the method. Start with simple examples and move onto include those that involve polyatomic ions. Ensure students understand that the number ‘1’ is not written in formulae. Digital Crossover method presentation C5c Properties of ionic compounds C1.32 Explain the properties of ionic compounds limited to: Set up a circuit with a low voltage power supply, graphite electrodes and a lamp. Students test six substances and identify which of them are ionic compounds. Explain what happens during electrolysis using a model or digital animation. If a
a high melting points and boiling points, in terms of forces between ions b whether or not they conduct electricity as solids, when molten and in aqueous solution Place the electrodes into a spatula of solid sodium chloride crystals in a small glass beaker and show that the lamp does not light up – so solid sodium chloride does not conduct electricity. Remove the electrodes, add about 40 cm3 distilled or de-ionised water to the beaker of sodium chloride and stir to dissolve as much as possible. Replace the electrodes and the lamp lights, showing that sodium chloride solution does conduct electricity. Ask the students to explain these observations Equipment d.c. power supply, connecting leads and crocodile clips, two graphite electrodes, lamp in a holder, 100 cm3 glass beaker, glass rod, sodium chloride (salt) crystals, distilled or water, optional: Students should find that copper sulfate, potassium iodide and sodium chloride are ionic compounds. Ethanol, sugar and water are not ionic compounds. Equipment each group needs: boiling tube with bung to fit, 100 cm3 beaker, d.c. power supply, dropper pipette, eye protection, two graphite electrodes, lamp in a holder, leads and crocodile clips, spatula, substances to test – copper sulfate, ethanol, potassium iodide, sodium chloride, sugar and distilled or de-ionised water magnetic model is available, the ions can be separated to represent melting and they can then move from one electrode to another, so molten ionic compounds do conduct electricity. Emphasise that charged particles that can move are needed for a substance to conduct electricity. Ionic compounds always contain ions, which are charged particles. Show that the ions are held in fixed positions in the solid state so they cannot move from one electrode to the other, and so solid ionic compounds do not conduct electricity. Equipment d.c. power supply, lamp in a holder, two graphite electrodes, connecting leads and crocodile clips, evaporating
sticky notes or basin, spatula, Bunsen burner, tripod, gauze, heat-resistant mat, goggles or face shield, zinc chloride (few grams), model of an ionic compound, blue litmus paper Access to a fume cupboard Optional: magnetic model of an ionic compound, webcam or video projector Digital: TBC C6a Covalent bonds C1.28 C1.29 C1.30 Explain how a covalent bond is formed when a pair of electrons is shared between two atoms Recall that covalent bonding results in the formation of molecules Explain the formation of simple molecular, covalent substances, using dot and cross diagrams, including TBC TBC TBC
Biology Spec points covered Starter Practical activity Teacher-led activity CP3a Energy stores and transfers P1.29 P1.30 P1.31 P1.32 Explain, with examples, that, where there are energy transfers in a system, there is no net change to the total energy of a closed system Analyse the changes involved in the way energy is stored when a system changes, including: a an object projected upwards or up a slope b a moving object hitting an obstacle c an object being accelerated by a constant force d a vehicle slowing down e bringing water to a boil in an electric kettle Use diagrams to represent energy transfers and calculate the before and after energy values Explain that, in all system Ask students to write a short story to illustrate different energy stores and transfers. Students can either highlight or label the different energy stores/transfers in their stories, or volunteers could be asked to read out their stories and the class identify the stores and transfers as the story is read. They could also be asked to suggest any transfers or stores not mentioned in the story. Students work in pairs or small groups, depending on the availability of equipment, to undertake a series of brief practical investigations to observe a series of energy transfers from one store to another Students identify the energy stores and transfers involved in each demonstration they look at. Equipment battery-powered torch (could be a circuit with cell and lamp); electric motor (could be set up to lift something); baby’s rattle; microwave oven; a solar cell (could connect to output device like a fan, or just to a voltmeter); a weight going over a pulley to drag a wooden block along the desk (this could be a dynamics trolley); radio; torch; toy on a spring that bounces up and down; computer animation of a nuclear reactor in operation (the computer’s energy Set up a simple pendulum and start it swinging. Elicit the idea that the initial store of gravitational potential energy from lifting the bob is transferred to kinetic energy and back to potential energy, and that air resistance (and friction in the pivot) will eventually slow it to a stop. This happens as the moving pendulum transfers some of its kinetic energy to kinetic energy of the surrounding air particles. Eventually all the energy initially given to the pendulum will be transferred by heating to the surroundings. Then drop a ball onto the bench, and let it bounce until it stops. The energy changes here are between gravitational potential
changes, energy is dissipated so that it is stored in less useful ways transfers could be an additional discussion question); a Bunsen burner heating water (include a thermometer clamped to show the temperature - heated water will need to be replaced by cold water regularly); sonometer or stringed instrument (the instructions should include pausing when the string is stretched so that elastic potential energy is included.) energy, kinetic energy and elastic potential energy when the ball deforms on hitting the bench. As before, all the gravitational potential energy originally stored in the ball is eventually dissipated to the surroundings by heating. Equipment: Pendulum: clamp and stand; weight; string or thread Bouncing ball: ball that bounces several times before stopping Digital Explaining properties animation CP3b energy efficiency P1.38 P1.39 Calculate efficiency in energy transfers, and explain how efficiency can be increased Recall and use the equation: efficiency = (useful energy transferred by the device) Draw two Sankey diagrams on the board for similar appliances with the same energy inputs but different proportions of useful and wasted energies output. Students work out the efficiency of an electric kettle by measuring the time taken to boil water. Students then calculate the efficiency of the kettle in boiling the water. Kettle efficiencies should generally be quite high (of the Find one or more news reports on the internet from 2014 when an upper limit on the power of new vacuum cleaners was imposed and resulted in panic buying before the deadline. Explain that
P1.33 P1.36 (total energy supplied to the device) Explain that mechanical processes become wasteful when they cause a rise in temperature so dissipating energy in heating the surroundings … Explain ways of reducing unwanted energy transfer including through lubrication ... Ask students to describe what the two diagrams show, elicit ideas about the differences between the energies transferred by the two objects, and discuss what could be used as the measure of energy wasted – elicit the idea that comparing the amount of useful (or wasted energy, at this point in the lesson) to the total energy transferred to the appliance is a more useful measure than just looking at the amount of wasted energy. order of 0.8 or above). Equipment: electric kettle(s) with auto-shut-off (If various kettles with different power ratings can be provided, then this experiment can be repeated to find out, for example, if higher power kettles are more or less efficient.); measuring cylinder/beaker (500/1000 ml); stopclock Optional: temperature sensing datalogger. power is a measure of energy transferred each second, and ask for suggestions why this was done. Question students to elicit the idea that the limit on power will encourage manufacturers to develop more efficient machines, so that they end up with a vacuum cleaner that uses less energy for the same performance. Digital Efficiency calculations presentation CP3c Supplying electricity P1.33 P1.34 Explain that mechanical processes become wasteful when they cause a rise in temperature so dissipating energy in heating the surroundings or when they do electrical work against resistance of connecting wires. Explain why electrical energy is transmitted at Hold a short brainstorming session to elicit words connected with the transmission of electricity around the country (e.g. power station, pylon, cables, substation). Ask students to suggest what these things are for, and then to work in pairs or small groups to write a short Students to compare the energy transferred by a bulb close to a power pack and connected to the power pack by lengths of resistance wire. Students should find that the energy transferred to the distant bulb is significantly less than to the bulb close to the power pack. Demonstrate the effect on transmission losses of increasing the voltage of a supply by using a 12 V a.c. supply connected to two metre-long lengths of resistance wire. Connect a bulb across the supply and another across the ends of the resistance wires. Switch
P1.35 P1.36 high voltages, as it improves the efficiency by reducing heat loss in transmission lines Explain where and why and step-down transformers are used in the transmission of electricity in the National Grid Explain ways of reducing unwanted energy transfer including through … lubrication, thermal insulation and low-resistance wires paragraph to explain their ideas. Equipment: power pack; 2 x 1 metre lengths of 24 SWG nichrome wire; connecting wires, crocodile clips; 2 12 V bulbs, 2 voltmeters, ammeter on and ask students to compare the brightness of the two bulbs. Then connect a transformer to the output of the powerpack, set up to increase the voltage to 240 V, and another at the other end to step it down to 12 V again. For this part of the demonstration the lengths of resistance wires should be insulated inside a plastic sleeve. Ask students to compare the brightness of the bulbs. Equipment:12 V a.c power supply; connecting leads and crocodile clips; 2 x 1 metre lengths of resistance wire; 2 transformers, set up with a turns ratio of 20; 2 x 12 V bulbs.
Optional: 2 mulitmeters Digital National grid interactive CP3d Keeping warm P1.36 P1.37 Explain ways of reducing unwanted energy transfer including through … thermal insulation Describe the effects of the thickness and thermal conductivity of the walls of a building on its rate of cooling qualitatively Show students some images of energy-efficient houses, and ask them to explain what it means to refer to a house as 'energy-efficient'. Ask for suggestions as to what features of the house help with this and why, eliciting ideas about various insulation methods (e.g. double glazing, loft insulation, cavity walls, etc). Students test the effectiveness of different types of insulation. Water in beakers with insulation will cool down more slowly than in the control beaker. The rate of cooling will depend on the type and thickness of insulation used. Equipment: kettle, 3 250 cm3 beakers, lids for beakers (discs of card with a hole for the thermometer), 3 thermometers, stopclock, selection of insulating materials (e.g. bubble wrap, fleece, various types of cloth, paper towels), sticky tape. Optional: temperature sensors and data logging equipment. Wrap a piece of paper around the junction between the wood and metal in a wood and metal bar. Gently play a Bunsen burner flame on the paper. Students should be able to see that the paper that is over the wood begins to scorch; the paper over the metal does not. Elicit reasons for this (the metal bar conducts the energy throughout the bar, so does not get as hot where the Bunsen flame is heating it). Ask them to describe the wood and the metal in terms of their thermal conductivities.
Digital Non-renewable energy video CP3f P1.40 P1.41 Describe the main energy sources available for use on Earth (including fossil fuels, nuclear fuel, bio-fuel, wind, hydro-electricity, the tides and the Sun), and compare the ways in which both renewable and sources are used Explain patterns and trends in the use of energy resources Write the phrase ‘NIMBY’ on the board and ask students if anyone knows what it means. If necessary, tell them that it stands for ‘not in my back yard’, and ask them to suggest why this phrase is often used when talking about people who are protesting against a new wind farm or other Students investigate the factors that affect the output of a solar cell, starting with the link between output current and the distance from the light source, then planning how to investigate a different factor. The voltage will reduce as the lamp is moved further away. Equipment solar cell, voltmeter (or multimeter), connecting wires, lamp, ruler, Discuss what happens to the demand for electricity when a very popular TV programme finishes or when there is an advert break (e.g. during a live cup final or a popular soap). Elicit the idea that lots of people all getting up to put the kettle on at once will cause a sudden demand. Ask students to suggest