Spicing up Science
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Science with a Bang
Suggestions to make science lessons more engaging and exciting for teachers and students alike.
Science Learning Centre South West
Hosted by Neil Adams Cirencester Deer Park School . With huge thanks to Nick Barker, Royal Society of Chemistry Teaching fellow, University of Warwick. Steve Hacker Science Network Co-ordinator, SSAT and Ken Stook, legend amongst lab techs, Cirencester Deer Park School
Science with a bang. 1 Neil Adams Science Learning Centre South West Introduction and safety issues This document contains ideas for activities that you can do in your classroom to engage and inspire young people (and old if you need ideas for Open Evenings). All the ideas included have been carried out and evaluated at Cirencester Deer Park School. They are not necessarily new but we have tried to group them together in one place. We have carried out risk assessments on these ourselves. However if undertaking any of these activities please ensure you carry out your own risk assessments appropriate to your institution.
Table of Contents
Page
Spectacular spectroscopy 3
Quickie motors 4
A big Heart 5
Big Moments 5
The wall of flame 6
Air power 7
Elephants trunk 9
Catching laser light 10
A different sort of electrolysis 12
A Big Bang 12
Science with a bang. 2 Neil Adams Science Learning Centre South West Activity 1: Spectacular spectroscopy
The idea Use the flame tornado to give a different flavour to teaching flame colours or other aspects of spectroscopy.
Requirements: Two sheets of aluminium or steel gauze, a Lazy Susan (turntable) , lighter fluid or other flammable material, suitable heat resistant container. A variety of different salts (Cu, Ba, Sr all give great flame colours)
The series images further explains the construction.
Safety: Do not spin turntable too fast and take care of flammable liquids which produce soot Ignite the liquid. Place gauze cylinder around flame. Turn the turntable.
Stimulus questions Why does the flame shape change? What is happening to the movement of air? What do you notice about the direction of the twist in the flame? Link to film Twister
For further information go to: http://www.uwe.ac.uk/fas/graphicscience/flame_tornado.htm
Now for the spectroscopy part.
Repeat the experiment but this time add a salt to the burning dish.(Note: this works best by adding a few drops of water to the salt and then mixing with ethanol)
Pupils can then look at the flame through diffraction gratings.
Alternatively spray a salt/water/alcohol mixture through the gauze. They can make verbal reports on what they see to the rest of the group. Stimulus question Why do we see different patterns?
Science with a bang. 3 Neil Adams Science Learning Centre South West Activity 2: Quickie motors
The idea Stop all that messing about with Westminster motor kits. Here is a sure fire way of getting a working motor to use for pupil self-demonstration
Requirements: One AA battery, one piece of insulated wire cut to 16cm, one cube magnet (available from www.guysmagnets.com), one ferrous screw or nail.
Assembly
Place the magnet on the end of the screw as shown below.
Now place the magnetised screw and magnet to the base of the battery and bring the wire from the top of the battery to the magnet.
( the lower end of the wire is a “brush” and needs to be splayed out to make good contact with the magnet.
You should now be able to suspend the screw from the battery and when the wire makes contact it should create movement
Stimulus questions Why does the magnet turn? Why does it keep turning long after the connection is broken? What are the requirements for an electric motor?
Activity 3: A big heart
Science with a bang. 4 Neil Adams Science Learning Centre South West The idea Heart dissections have long been a favourite of biology teachers and pupils alike,. The aim here is to make the dissection more spectacular. The use of a large OX heart does the job. Students are fascinated by the size of it compared with ones they have previously seen dissected. Also its size means more can see what you are dissecting. Projecting it onto a screen in the room adds event more detail. Requirements: An ox heart, dissection equipment, video camera/ webcam/visualize
Safety issues: take care with sharp scalpels as with normal dissection equipment.
Stimulus questions What does the heart do? Why is it so large? How would a mouse heart appear?
Another excellent dissection (and an easy one for the faint of heart) is a chicken leg. Being bloodless and pretty much food it is less threatening but a superb chance to see arrangements of muscle, tendon and ligament around a joint and to see what cartilage does.
Activity 4: Big moments The idea Trying to demonstrate moments using small moments kits can be difficult. Here you balance a plank of wood on a large piece of drainage pipe
Requirements: A wooden plank, large piece of pipe (drainage) Safety issues: the plank is heavy and with younger pupils take care carrying it. Pupils sit in a circle around a giant “See-Saw” in the middle of the room. You can then move the pivot point to show relative ease/ difficulty. You could try to lift a class member. The aim is to ensure that that pupil shave a feel for what is happening way before you introduce any maths! Use the original final scenes from Italian Job as a focus for further discussion here.
Stimulus questions When is it easiest /hardest to lift someone? Why does the position of the pivot make a difference?
Activity 5: The wall of flame
Science with a bang. 5 Neil Adams Science Learning Centre South West The idea You create a sense of awe about energy released from a normal foodstuff.
Requirements: Powdered milk, spirit burner / blowtorch or Bunsen burner, safety goggles.
Safety: This needs practice! Make sure you step back after the powder is released.
Stand on table with spirit burner/Bunsen burner on the floor. 50 cm in front of you. Sprinkle a generous quantity of powdered milk into the vicinity of the burner. Full fat milk is better than skimmed and the more finely powdered brands work better. The milk will ignite and produce a curtain of flame. With skill, practice and bravery you can achieve a wall of flame 2m high.
Stimulus questions How can milk burn? What might be in it that is flammable? Link this to rates of reaction and discuss industrial safety.(Coal dust explosions in mines) At high levels discuss how powder could smother a flame or cause explosions. Link to stoichiometric gas ratios.
Science with a bang. 6 Neil Adams Science Learning Centre South West Activity 6: Air power
The idea Use the air cannon to show how air can move and that it can use this to stimulate discussion about weather , explosions etc.
This is a really lovely demonstration in a room with good lighting. Spotlighting, such as in a school hall can make this really spectacular.
You can buy vortex launchers (air-zookas) from toy shops or the internet.
They’re very good but don’t have the capacity for being filled with lots of smoke and don’t generate such a stable, low-speed vortex.
How to make an air-cannon
Requirements: For a big smoke ring launcher you’ll need a cheap, round plastic bin. A pound shop special is ideal – look for that waxy-feeling plastic that’s easy to cut. You’ll also need a rubber sheet. I used a cheap shower curtain for this and it worked superbly.
1. Carefully mark out a circle on the base of the bin. It needs to be dead centre – fortunately the cheap bins usually have a centre point marked from the moulding! The circle should be about half the diameter of the bottom of the bin. Size isn’t crucial – you may even want to make a couple and investigate how the size affects the performance and speed of the vortex.
2. Cut the circle out with a sharp knife. This is crucial. The stability of the vortex in the air is far greater if the hole is circular. Aim to be lightly inside your line if anything, you can always improve the shape then by shaving off the excess plastic carefully.
3. Cut a circle of shower curtain (or rubber) that’s about 10-15 cm outside the rim of the open end of the bin. Place the bin, open end down (new hole up) on the centre of the circle of sheeting and use a couple of strips of gaffer tape at 12 and 3 o’clock to hold it in place. Invert the whole thing.
Science with a bang. 7 Neil Adams Science Learning Centre South West Apply some tension to the sheet and gaffer tape the rest of it in place at regular intervals so that the sheet is under tension. Not like a drum skin, just not flapping about.
4. Now seal off the edges of the sheet with generous quantities of gaffer tape. It should be airtight. Your launcher is ready for use.
Using the smoke-ring launcher. Cradle the launcher in one arm and tap the centre of the sheet gently with the flat of your hand. It will launch a toroidal vortex of air out of the hole. If you use a smoke generator to fill the bin, you will blow smoke rings. Experiment with how hard you tap the sheet – see how it affects the size and stability of the smoke rings. You can make a ‘blank’ from thick, strong cardboard and tape it to the front of the launcher to vary the size (and, if you wish) the shape of the rings. (moving from a circle to a square with rounded edges may help bright students to develop a model for vortex formation. With a little practice you can blow out a candle at thirty feet!
Stimulus questions Why does the smoke ring have that shape? What is happening to the movement of air? What explanation can you give for the accuracy of the air cannon?
For further information go to: http://www.stevespanglerscience.com/experiment/00000076
Science with a bang. 8 Neil Adams Science Learning Centre South West Activity 7: Elephant’s Trunk
The idea A memorable demonstration of the affect of a catalyst on a reaction.
Safety: hydrogen peroxide is harmful, use with care, wear skin protection and eye-protection
Requirements: Hydrogen Peroxide – (the most concentrated stuff you can find), washing-up liquid, Potassium Iodide powder (the catalysts), a large desert spoon, big (5 litre) measuring cylinder, black bin liner.
Method: 1. Tip: do this on an opened out bin liner! 2. Pour hydrogen peroxide into the large measuring cylinder to a depth of about 10 cm. 3. Add a good slug (5 seconds of pouring) of washing liquid and swirl to mix 4. Pour in about a desert spoon full of KI powder! 5. Don’t play with the foam; it contains iodine and will stain you and your clothes! 6. You can try adding food colouring to the hydrogen peroxide but I don’t think it does much! 7. Bundle up the foam in the bin liner and let the bubbles die away.
The bubbles are filled with oxygen as you can see if you stab at them with a glowing splint!
Stimulus questions Where does the oxygen come from? (share the formula of Hydrogen peroxide) Why is the oxygen released so rapidly? What other catalysts could you use?
Science with a bang. 9 Neil Adams Science Learning Centre South West Activity 8: Catching laser light (Total Internal Reflection) Requirements: Side arm test-tube, laser pointer, water supply Safety issues: laser light must not be pointed into eyes. Take care when positioning the laser.
Extend this into the use of fibre optic cables. Link to the film Entrapment starring Catherine Zeta-Jones, Sean Connery Use the Interactive Optics program. You will find the link to a free download below. Stimulus questions Why doesn’t the light escape? How can you catch it? Are you really catching light?
For a free download of the Interactive Optics program click here. www.deerparkschool.net/data/cdpsDev/OpticsSetup.exe
Activity 9: Making Iron on a Match Head The idea Use this when teaching about the Blast Furnace!. It is really effective
Requirements: Box of matches, Iron oxide powder (iron III oxide is fine), Sodium Carbonate powder, Watch glass, Magnet
Method:
1. Dip the head of a match in water. 2. Roll the damp match head in iron oxide powder and then sodium carbonate powder so that it builds up a coating of both powders that is maybe 1mm thick. 3. Use a second match or a flame to ignite the powdered match! 4. Blow out the powdered match when it has caught fire and burned for a couple of seconds. 5. Carefully scrape off the match head from the now extinguished powdered match onto a watch glass. (A spatula works well for this) 6. Grind the match head into a powder. 7. Move a magnet under the watch glass and see the iron fragments move in the watch glass.
See worksheet
Science with a bang. 10 Neil Adams Science Learning Centre South West Iron is usually found within the Earth’s crust as a rocky ore. The iron ore is converted to iron metal in a blast furnace.
The following experiment shows this process on a mini-scale.
Put on Safety Glasses
Take two matches
Wet the end of one match
Dip it first into Iron Oxide (orange powder), then Sodium Carbonate (white powder)
Ignite the 2nd match and use this to light the 1st match – then blow out both matches
Using a spatula, scrape off the end of the 1st match onto a watch glass and crush it with the end of the spatula
* Caution – the end of the match will be hot! *
Move a magnet under the watch glass and see what happens
You have made iron!
Science with a bang. 11 Neil Adams Science Learning Centre South West Activity 10 Different Electrolysis Experiment
The idea Electrolysis is a frequently used experiment in KS3 and 4 but can be dull. Here is a way to spice it up.
Requirements Strip of chromatography paper, 2 microscope slides, Potassium permanganate crystals, Tweezers, Lab pack (20V D.C.), Connecting leads – plug/croc clips,Water from the tap
Method: Tip: Practise setting this up before you add the chemicals!
1. Place a piece of chromatography paper on the top of a microscope slide and make a pencil mark in the centre of the paper. 2. Wet the paper with tap water and drain off any excess. 3. Use tweezers to add a tiny crystal of potassium permanganate to the pencil line. 4. Put another microscope slide on top to stop the filter paper from drying out.
Activity 11: A big bang The idea To convey the idea that an enormous amount of energy is released when you get the proportions of gas correct. Check: Are you allowed to do this at your school? It makes a very loud explosion. Open all windows and ensure that students have their hands cupped over their ears not fingers in ears. Also be sensitive to students who have colds as blocked sinuses and Eustachian tubes can cause discomfort after the bang.
As demonstrator use ear plugs that you can get from motorcycle shops.
A one litre plastic beaker, Water from the tap, Washing-up liquid, a glass rod, 20% hydrogen peroxide, Manganese (iv) oxide powder and spatula, 2mol/dm3 Hydrochloric acid, Mg ribbon pieces, 2 x 250ml conical flasks, 2 x right angle delivery tubes with bungs, taper on the end of a metre stick
Method: 1. Simultaneously bubble hydrogen and oxygen into the soapy water until the bubbles are about level with the top of the beaker. 2. Remove the delivery tubes 3. Ignite with a burning taper on a stick. (do not mistake taper for tapir) 4. Half fill the plastic beaker with water and stir in some Fairy Liquid
Science with a bang. 12 Neil Adams Science Learning Centre South West Appendix
Activity 1: Light Olympics Requirements: Ray boxes, mirrors and prisms. The challenge is to make a beam of light from a ray box travel the longest distance possible. Stimulus questions What determines the brightness of the beam? How far can the beam stretch? Why does the ray seem to fade? How could we use a control in this experiment? What if we used a different colour of light?
Activity 2: The coke can spirit burner.
For a step by step guide, see http://www.youtube.com/watch? v=eRt8mNOP2b0&feature=related
Activity 3: The half life of froth Requirements: One can of Boddingtons or other beer with a “widget” to create a head, measuring cylinder, stopwatch, ruler, spreadsheet, printer. Open can and pour into measuring cylinder let bubbles settle into a head then start the stop watch. Use the ruler to measure the depth of the head. Record results into a spreadsheet and plot the decay graph. Link this to radioactive materials. When a bubble bursts it is like an atom decaying. Stimulus questions Can you determine which bubble will burst and when? Why does the graph have the shape it does? What other materials might have a half life?
Science with a bang. 13 Neil Adams Science Learning Centre South West Activity 4: Flaming bubbles Requirements: One bubble mixture,2 litre pop bottle with bottom cut off, rubber tubing, stopper, glass tube. Place bubble mixture in upturned bottle. Bubble gas through it. Create bubbles. Collect sample of bubbles and ignite them in your hand. Stimulus questions Where does the energy come from? Where does the heat go? Why do you need to wet your hands? What is produced when burning happens
Activity 5: The baseball bat trick & bed of nails The idea for these Making examples to do with pressure tangible Requirements for the baseball bat trick. (This is a great one. It gives students a clear visual representation of the way that a large force can be distributed over a large area.) One large board (chip or block board works well, a large sheet of sponge foam, one volunteer, baseball bat or crow-bar. Safety: take care that the board is correctly located and not likely to catch chin of volunteer. Hold bat or crow-bar tightly. Ensure area is clear for a good swing. Volunteer lies on flat surface. Lay foam on chest. Lay board on top of foam. Lift baseball bat high. Hit the board.
Requirements for the bed of nails. Obviously you will need to make a bed of nails. It took approximately 2 hours once the components had been purchased. (If you want to make the bed of nails follow the link to the instructions sheet)
Science with a bang. 14 Neil Adams Science Learning Centre South West Science with a bang. 15 Neil Adams Science Learning Centre South West You will also need two bricks, cinder block and a sledgehammer. Drop an apple onto the bed of nails. Then the volunteer lies on bed of nails, holds board and foam on chest. Place the block across two brick on the board. Alternately, if you’re feeling tough and you’re in reasonable physical shape, just rest the cinder block on your chest and stomach, flatten your abdominal wall so that there is good contact with most of the front of your body and make sure your volunteer knows how easily a cinder block can be broken!
Then hit with sledgehammer. Take care when hitting the block for flying debris. Use safety specs for the breaking of bricks. Volunteer should also wear safety specs.
Stimulus questions Why is the volunteer unhurt? What happens to the force? Why does the apple get damaged but despite the force the volunteer remained unhurt? How do both tricks work? Get together in small groups to discuss.
Science with a bang. 16 Neil Adams Science Learning Centre South West Activity 6: Defying gravity Requirements: Two copper tubes, ball bearings, spherical magnet, retort stand Drop the ball bearings simultaneously down the copper tubes. Have pupils ready to catch them. On is obviously a magnet not a ball bearing. As it travels down the copper tube it sets up currents in the electrons in the copper. This creates a magnetic field which opposes the movement. Stimulus questions Why are there differences in speeds? What could cause these differences? Is there anything special about the tubes or ball bearings?
Activity 7: Plasbots - Explaining genetic diagrams Requirements: Plasticine, Poppit beads, drawing pins, wire Build two small plasticine animals, give them eyes in two different colours, curly tails, etc Discuss with students that the external appearance or features is described by the word phenotype. Use these features to explain dominant and recessive genes and also genotype and phenotype as shown. Write the genotypes into Punnett squares on poster paper of flipchart. Get students to make models of all the possible offspring and place them in the correct place according to their genotypes. Stimulus questions How might green eyes come about? What if the genes are the same? What if the genes are different? Links The link to the Bug Lab site is really good. You can change environmental conditions as well as getting males and females to mate. You can study sex inheritance. http://www.channel4.com/learning/microsites/G/genetics/activities/buglab.html
Another link is to show the first 30mins of the film GATTACA. This is excellent for promoting discussion about the ethics of genetics. Show it up to the part where the main character goes to an interview and gets the job based solely on his genotype. It gets to children of all aptitudes. It links brilliantly with the new KS4 programme of study.
Science with a bang. 17 Neil Adams Science Learning Centre South West Instructions for Teachers
A word of caution:
Practise all of these before you use them and remember that it is up to you to do a risk assessment for each demonstration that is relevant to your institution. I recommend you use a safety screen and have your audience wear eye protection. You will need to wear eye protection and I suggest also wearing a lab coat and washing up gloves to add to both your safety and the general spectacle!
Activity 8: Perfect Combustion
Apparatus:
A PowWow water dispenser bottle, empty and dry Methanol Matches or taper on a stick Beaker
Method: 1. Pour in approximately 100ml of methanol from a beaker into the Pow Wow bottle. 2. Put your hand over the top of the bottle and swirl the contents. Do not coat your hand with methanol! 3. After around 20 seconds pour the remaining liquid out of the PowWow bottle back into the beaker and remove this from the vicinity of the demonstration. If you have built up a good amount of methanol vapour in there you will hear a hiss as you remove your hand from the top of the bottle. 4. Keep yourself well away from the top of the bottle and slowly move a lighted taper on a metre ruler over the top of the bottle. 5. After the flame has gone out you can invert the bottle to show water has been produced.
Science: Blue flame as perfect combustion. Water vapour is a product of combustion.
Science with a bang. 18 Neil Adams Science Learning Centre South West Activity 9: The Collapsing Lemonade Bottle
Apparatus: 2 litre plastic lemonade bottle (that can be squashed obviously!) with lid To make carbon dioxide with which to fill the bottle: Some dry ice works best of all – you’ll need a CO2 fire extinguisher and a tea towel for that Or: a conical flask, calcium carbonate and hydrochloric acid. You need a delivery tube that can get to the bottom of the bottle really – a bit of rubber tubing on the end is fine! A bottle (500ml) of 1M NaOH solution.
Method:
Fill the lemonade bottle with carbon dioxide Pour in 100 ml of NaOH solution and screw the top onto the lemonade bottle As the gas dissolves in the water it forms carbonic acid. The alkali takes this out of action more gas can dissolve causing the pressure inside the bottle to drop and the bottle to collapse under atmospheric pressure.
You will need lots of carbon dioxide in there if it is going to work well!
Activity 10: Match rockets
Side vents formed by pins allow gases from head to propel rocket forward. Excellent starter for Newton’s Laws. Stimulus questions What makes the rockets fly? Why don’t they fly straight? How can they be made to go further/straighter? This activity can be extended into making ballistic launchers from Pringles tubes. This is huge fun but needs a carefully conducted risk assessment. See the book ‘Backyard Ballistics’.
Science with a bang. 19 Neil Adams Science Learning Centre South West Science with a bang. 20 Neil Adams Science Learning Centre South West Science with a bang. 21 Neil Adams Science Learning Centre South West Activity 11: Money tricks.
The non-burning fiver is an old Leonard de Vries trick. It’s very easy to do. Simply soak the money in a 50/50 ethanol water mix or, if you’re simply showing off in a cocktail bar, a glass of neat vodka. The alcohol will burn off but the water will absorb sufficient heat that the paper never gets hot enough to burn. You could see whether a good A-level class could work out what the minimum and maximum ratios should be and test the theory. Link here
The other trick is also straightforward and relies on the water to absorb the heat but also on the conductivity of paper. Simply fold the note into a ‘canoe’ shape, fill it with water and the water can be heated and even boiled in the flame. This will make the paper sooty but banknotes, due to their high linen content, can be washed. (An excellent question for pupils who have been to the US here: why are dollars easier to forge than pounds sterling?) If you’re doing this as an open-evening activity, fill a Zippo with ethanol and you won’t dirty your volunteers’ money too badly.
Activity 12. Lenz’s Law
This is incredibly simple. Take a spherical magnet and a ball-bearing of equal size. Find a copper pipe with an internal diameter slightly larger than that of the magnet and ball and clamp it vertically. Pick an opponent from the class and challenge them to beat your reflexes. It is a trick that a class will see through quickly but the explanation takes a little more working out...
Science with a bang. 22 Neil Adams Science Learning Centre South West Bibliography and other resources
Video resources Gattaca Twister Entrapment The Italian Job (1960s version)
Internet resources Steve Spangler science http://www.stevespanglerscience.com/ Educational Innovations http://www.teachersource.com/ Guysmagnets http://www.guysmagnets.com/ Smoke machines http://www.smokemachines.net/buy-z800.shtml Lots of links and ideas http://scitoys.com/ Coke can stove http://www.youtube.com/watch?v=eRt8mNOP2b0&feature=related
For a free download of the Interactive Optics program click here www.deerparkschool.net/data/cdpsDev/OpticsSetup.exe
Books Backyard Ballistics (Independent Publishers Group) ISBN 1556523750 Electronic gadgets for the evil genius (McGraw-Hill) ISBN 0071426094
Science with a bang. 23 Neil Adams Science Learning Centre South West