20 amazing facts about the human body
Category Archive: GCSE
Permanent link to this article: http://www.animatedscience.co.uk/2013/20-amazing-facts-about-the-human-body
Can science stop the stink bug invasion? http://www.bbc.co.uk/news/world-us-canada-22115507
Permanent link to this article: http://www.animatedscience.co.uk/2013/can-science-stop-the-stink-bug-invasion
One rat brain ‘talks’ to another http://www.bbc.co.uk/news/science-environment-21604005
Permanent link to this article: http://www.animatedscience.co.uk/2013/one-rat-brain-talks-to-another
This is a set of cool Chemistry / Physics demos which can be quite exciting and dangerous. They are not mine so I take no resposibility for each one or how you apply it. I have only put them here for reference to give you some ideas!
Methane Bubbles. Methane from a natural gas line or a lecture cylinder is connected via a piece of rubber tubing to a very small funnel. After a slow flow is started, the funnel is put into a petri dish containing bubble solution. This takes practice but it is possible to produce bubbles which when shaken free of the funnel rise into the air. The bubbles are ignited with a Bunsen burner or a barbecue lighter. The same experiment is repeated with air if it is available. The burning bubbles are most dramatic in a darkened room. Be sure to have a fire extinguisher handy when you do this experiment and be careful not to ignite the methane anywhere but at the bubbles.
1. A balloon is attached to a piece of vacuum hose with a hose clamp. The other end of the hose is connected to a plastic bottle containing a small amount of liquid nitrogen.
2. An inflated sealed balloon is slowly pushed into liquid nitrogen. Balloons that have bulges or twists are preferred. After the balloon has shrunk to a minimal size, it is allowed to warm to room temperature. If a helium filled balloon is used and the balloon is released in the liquid nitrogen, it will eventually warm up and float to the ceiling.
3. After liquid nitrogen is added to a plastic bottle, a rubber stopper is securely inserted into the bottle. After several seconds it will shoot out into the audience if aimed properly.
4. Into the plastic bottle containing liquid nitrogen, insert a rubber stopper with a 25 cm long piece of 7 mm tubing that reaches to the bottom of the bottle. A fountain will quickly result and if sufficient nitrogen is used, it is possible to almost disappear in the descending fog. The rubber stopper should be held in carefully as on rare occasions, liquid nitrogen runs down the glass tube and can freeze your hand.
5. A marshmallow is placed on a copper wire and inserted into liquid nitrogen. After about 3 minutes, gentle tapping in a beaker will shatter the marshmallow.
6. Liquid nitrogen can be harmlessly poured quickly on the back of your hand for very short periods of time.
7. Have the children separate if the floor is carpeted and leave a wide aisle and throw some liquid nitrogen onto the floor between them.
Welcome School Sign. A 5% aqueous potassium ferrocyanide solution is used to write “Welcome” and a 5% aqueous potassium thiocyanate is use to write the name of the school. The sign is sprayed using a pump sprayer with a 1% aqueous solution of iron(III) chloride.
Paper chromatography. Felt tip pens are used to spot a piece of Whatman #1 chromatography paper cut appropriately (11 x 19.5 cm) to fit a 600 mL beaker. The paper is suspended with a large paper clip on a pencil. When water is used as the solvent, the separation is not complete but sufficient for students to see separation and differences between different colors and the same color of different brands. About 40 mL of a 1:1:1 mixture of 1-butanol, ethanol and 2 M ammonia works much better with some brands and the mixture seems to be stable for long periods of time. It does require more time for preparation and it smells.
Vacuum Experiments. Plastic bell jars and portable vacuum pumps are available form commercial lab supply companies. The latter are rather expensive and a relatively good one is needed to pop the balloon. Around Easter, it is advisable to stock up on marshmallow chickens and rabbits.
Molecular Motion. A drop food coloring is added to tall 200 maL beakers containing room temperature and very hot water. The heater stirrer unit should be one that heats rapidly and does not have the word magnetic printed on the front.
Endothermic Reaction. Vials containing 20 g of Ba(OH)28H2O and 10 g of NH4SCN (other chemicals can be substituted such as Sr(OH)28H2O and/or NH4Cl but the reaction is not quite as dramatic). The formation of water and frost can be observed and the presence of ammonia detected by smell. The flask gets cold enough (-20oC) to condense moisture form the air. The condensation can be demonstrated by rubbing some of the frost with a finger. Some students near the front can be allowed to touch the flask and tell the other students that it is cold. Some students assume all chemical reactions evolve heat and confuse the frost with steam. The flask gets cold enough to freeze water added to the bottom of the flask and the flask can be frozen to a smooth surface using ice as glue.
Blue Bottle Experiment. The following four solutions are prepared and stored in plastic bottles and dropper bottles.
Solution A: 32 g KOH/500 mL water
Solution B: 40 g dextrose/500 mL water
Solution C: 0.04 g methylene blue/100 mL water
Solution D: 1 g resaurzin (tablet form)/100 mL water
Mix about 30 mL of solution A, 30 mL of solution B, 10 drops of solution C and 10 drops of solution D. Stir, allow to sit and turn pink and then almost colorless (several minutes the first time and shorter amounts of time later depending on the amount of stirring). Pick up the flask very carefully and give it one quick swirl to turn it pink. Continued stirring will turn the solution purple. The cycle can be repeated many times.
Exothermic Reaction. Fill a vial with KMnO4 that has been ground up with a mortar and pestle. Place about a pop bottle cap full in a Pyrex Petri dish and add a few drops of glycerol to the KMnO4. After several seconds, the mixture will start to smoke, crackle and eventually ignite. Unfortunately, the reaction also give off a nasty smell.
Canned Heat. In a Pyrex Petri dish, put a few mL of saturated aqueous calcium acetate solution (about 35g/100 mL). Add ethanol, mix, and pour off the excess alcohol from the gel formed. Ignite with a match and sprinkle some boric acid on the flame.
Clock Reaction. Prepare the following two solutions in plastic bottles:
Solution A: Dissolve 4 g of soluble starch in 1 L of boiling water. After cooling, add 2 g of Na2S2O5.
Solution B: Dissolve 2 g KIO3 in 1 L of water containing 0.3 mL of concentrated sulfuric acid.
Mix: 25 mL of solution A and 25 mL of solution B (about 13 seconds for color change)
Mix: 25 mL of solution A and 50 mL of water and then add 25 mL of solution B (about 55 sec.)
Mix: 25 mL of solution A and 50 mL of very hot water and then add 25 mL of solution B (about 30 seconds)
To turn this reaction into the Old Nassau (Halloween) reaction, add 10 mL of a mercuric chloride solution
(0.15 g HgCl2 per 100 mL H2O) to a flask followed by 25 mL each of A and B. After about 0.5 minutes,
the solution will turn orange and another 0.5 minutes later, dark purple. Be aware of the disposal hazards
of mercury(II) ion.
Oscillating Clock Reaction. Prepare the following solutions in plastic bottles:
Solution A: Dilute 206 mL of 30% H2O2 to 500 mL with water. [Note: Walter Rohr informs me that 27%hydrogen peroxide can be purchased under the trade name Baquacil Shock and Oxidizer from pool stores. Check with http://www.archchemicals.com/Fed/BAQCIL for location of stores.]
Solution B: Dissolve 21.4 g of KIO3 in 500 mL of water containing 2.2 mL of 18 M H2SO4.
Solution C: Dissolve 3 g of soluble starch in 750 mL of boiling water. To the cooled solution, add 11.7 g of malonic acid and 2.5 g of MnSO4H2O.
Mix: Equal volumes (for small audiences, 25 mL of each is sufficient) of solutions A, B, C in an Erlenmeyer flask. While the demonstration is dramatic in an Erlenmeyer flask, it is even more impressive if the solution is quickly transferred to a graduated cylinder as there is a spatial effect to the oscillations easily observable.
Nylon. In a glass bottle, prepare a 0.25 M adipyl chloride solution in cyclohexane. Transfer about 20 mL of this solution to a plastic dropper bottle. In a plastic bottle, prepare an aqueous solution containing 0.5 M 1,6-diaminohexane and 0.5 M NaOH. Put about 2 mL of the amine solution in a shallow dish or watch glass and while adding the acid chloride solution dropwise, slowly pull out the nylon with a looped copper wire.
Chemilumescence. Prepare the following solutions in plastic bottles:
Solution A: Dissolve 2 g of luminol (aminophthalhydrazide) and 2.5 g of NaOH in 1 L of water.
Solution B: 0.15% H2O2
Mix: 40 mL each of solutions A and B in a graduated cylinder. Sprinkle a few crystals of K3Fe(CN)6 into the cylinder for an interesting effect and then add a larger quantity for maximum light output. For a yellow emission, add after the blue emission is observed, a few drops of a solution of 1 g of fluorescein and 1 g NaOH in 100 mL of water.
Mercury shadowgraph. Fluorescence is demonstrated first using a precoated thin layer chromatography sheet with a fluorescent indicator. A short wave (254 nm) mineral is a convenient portable light source. Next, a shallow plastic bottle of mercury opened and placed between the light and the fluorescent screen. In a sufficiently darkened room, the shadows of the mercury vapor are easily observed on the screen. A little blowing on the mercury sometimes enhances the demonstration.
Fluorescence and Phosphorescence. Fluorescence can be conveniently demonstrated by writing on Whatman No. 1 filter paper with solutions containing 0.02% methanol solutions of Rhodamine B (caution – suspected carcinogen), fluorescein, or acridine orange. For phosphorescence, write on the filter paper with a 5×10-3 M solution of a polynuclear aromatic acid ( e.g., naphthoic acid, naphthalene sulfonic acid) in a 1 M NaOH solution. 2-Naphthol gives both fluorescence and phosphorescence under these conditions. After drying irradiate with the 254 nm line of a mineral light in a dark room.
Electric Pickle. This experiment should be performed in a well ventilated area or for a very short time only. Cut off the female end of an inexpensive cord and split the wires. Solder large sheet metal screws to each of the wires. Support a large dill pickle in some way that won’t require touching (we use a ring stand and a clamp) and insert the sheet metal screws into opposite ends of the pickle. Plug the cord directly into a socket and after several seconds smoke should start coming out of the pickle and shortly thereafter, it should start glowing. At this point, the lights should be turned out but remember to run this for a short period of time and be very careful not to electrocute yourself. Students should definitely be cautioned not to try this one at home. There have been several articles in the Journal of Chemical Education on this reaction in the mid 1990′s.
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Permanent link to this article: http://www.animatedscience.co.uk/2011/ks3-5-waves-animation
Here is a simple hangman game. It is based on pH for Y7 with a selection of words. However, you can also type in your own word for kids to guess using any 12 letters dynamically for any topic for revision or end of year fun. Suitable for all ages!
Permanent link to this article: http://www.animatedscience.co.uk/2011/hangman
If you fancy a quick 30s timer with sound for the projector or a game then here it is….
Permanent link to this article: http://www.animatedscience.co.uk/2011/30s-countdown-clock
If you need a quick science stopwatch for an experiement or a projector…
Permanent link to this article: http://www.animatedscience.co.uk/2011/science-stopwatch
Just click on the pictures of the animals to see a video….
Permanent link to this article: http://www.animatedscience.co.uk/2011/a-selection-of-animal-videos
I was thinking recently about the changes we have seen to GCSE science in the past 10 years. I cannot comment before this but for the past 10 years I have taught AQA Core Science and Additional Science for Y11. Also before this the AQA double award which was split into Y10/Y11 so you had two grades.
The first thing that amazed me is when the “How Science Works” agenda came into play AQA changed the science content by mixing half of Y10 with half of Y11 then removing some content and making it the “Triple” part so I would say that pupils after the changes covered less than before unless they did triple science.
This was not the worst part. Take for example Y10 Electricity pupils would have to do a two stage calculation for working out the energy loss in a transformer in the multichoice exam. It was very difficult to get 36/36 in the exam. However, now most of the maths has come out of the exams and they are much easier for pupils (who can read) to access. What has changed is that there are now a lot of trick questions based more in English tricks than science tricks.
It was very interesting that for the past few years I keep raising the issue within science forums and nobody wanted to admit that things had got easier. However as more changes came in for 2010 Y9 students….
The exams watchdog, Ofqual, said the new papers – designed to address concerns that science exams had become too easy – had “not gone far enough”.
Last year Ofqual said science GCSEs taken in 2007 and 2008 had contained too many multiple choice papers and had failed to challenge the brightest.
Improvements have already been made to this year’s paper, Ofqual said.
Ofqual previously ordered an overhaul of GCSE science qualifications and immediate action was taken to toughen them up for students sitting them last year and this year.
Now the watchdog says the new-look qualifications, due to be introduced in autumn 2011, have been sent back to the exam boards for more work.
A spokesman for the exam board AQA said: “We are addressing the issues that Ofqual has raised, and will be re-submitting our specifications for accreditation, whilst maintaining the innovations that teachers and subject communities have
In view of the issues that Science is having I would appeal to all students and teachers to look for a guide from history. Just thumb though the exams and the textbooks from 20 years ago for Physics, Chemistry and Biology. You will see the standards and what is expected. The gap between GCSE and AS is getting wider and you will need to make sure that if for example you wish to study AS Physics you keep to the old standards. Mathematics is constantly removed from the subject to “make is more accessible” to pupils who cannot access maths as really the subject is dying as it is so hard compared to some others. But in reality Mathematics is the language of Physics and was invented by Physicists trying to understand the world around them. If you cannot express things mathematically Physics simply becomes a talking shop and more like philosophy.
Also why when you look through these is books is so much taken out of the modern AS/A2 exams. I am now teaching about 2/3 of what I did for my A-level 15 years ago so why has it been dropped? Don’t we use op amps, rectifying circuits and transistors in our circuits any more? Well of course we do but now they are in the 1st year of a Physics or Electronics degree? Draw your own conclusions and remember you can learn more than the exam board wants and better than the rest. Learning about science is not dictated by the exam board and we can do much more than them.
Permanent link to this article: http://www.animatedscience.co.uk/2011/gcse-science-a-journey
I am starting to worry about how we teach Physics to the pupils of today. It seems increasingly obvious that we teach more and more about things that are really unimportant to science and less about the fundamentals.
For example we spent a lot of time on the new HSW curriculum on identifying the type of a variable i.e. categorical, continuous and similar. This allows the pupils to decide which graph type to draw in an ISA exam for AQA and similar boards. However, really is that a skill that they need in their everyday lives or society needs for scientists of the future?
Now try some of these video cartoon clips http://www.animatedscience.co.uk/flv/ from KOCE (also see list on that page).
When you start to think about it, why is school Physics not split like this for all pupils into five main sections. Then just look at the topics they are such simple fundamental things which everyone should know about for their everyday lives. Also the right way to teach for pupils who go onto to Uni and further!
How many pupils really know about how a wheel works or simple lever, possibly mans greatest inventions. However, somehow written out by the QCA from KS3 and KS4. On the select few who take A-Level Physics are supposed to learn about these basic things of life?
Even more interestingly to really see if school science has failed is ask these question to a pupil. “What do stars do”. They will all answer “emit light”. Then you refine it…. “apart from emit light” which is obviously a secondary thing. Then 99% will not know and neither will most adults either. So in fact it seems the people who write the GCSE Physics for the nation as the missed it out of all the specs.
Stars in fact create all the elements in the Universe and of course those which make up our bodies. So what do we teach about stars…. well we teach about life and death cycles but forget the major important thing.
So what am I saying? Well if you can please slip into your teaching some of the really important things which will still give us pupils who can think for themselves and be creative. Also make sure that every pupil who goes through your hands regardless of if the QCA tells you to teach it or not understands the idea of a lever!
Permanent link to this article: http://www.animatedscience.co.uk/2010/the-problem-with-teaching-physics-in-modern-times
Have some fun label the diagram….
Permanent link to this article: http://www.animatedscience.co.uk/2010/structure-of-a-leaf-ks45-biology
This is part of a great Wikipedia Article, read more here….
The Teller–Ulam design is the nuclear weapon design concept used in most of the world’s nuclear weapons. It is colloquially referred to as “the secret of the hydrogen bomb” because it employs hydrogen fusion to generate neutrons. However, in most applications the bulk of its destructive energy comes from uranium fission, not hydrogen fusion. It is named for its two chief contributors, Edward Teller and Stanisław Ulam, who developed it in 1951 for the United States. It was first used in multi-megaton-range thermonuclear weapons. As it is also the most efficient design concept for small nuclear weapons, today virtually all the nuclear weapons deployed by the five major nuclear-armed nations use the Teller–Ulam design.
Its essential features, which officially remained secret for nearly three decades, are:
- separation of stages into a triggering “primary” explosive and a much more powerful “secondary” explosive.
- compression of the secondary by X-rays coming from nuclear fission in the primary, a process called the “radiation implosion” of the secondary.
- heating of the secondary, after cold compression, by a second fission explosion inside the secondary.
The radiation implosion mechanism is a heat engine exploiting the temperature difference between the hot radiation channel, surrounding the secondary, and the relatively cool interior of the secondary. This temperature difference is briefly maintained by a massive heat barrier called the “pusher”. The pusher is also an implosion tamper, increasing and prolonging the compression of the secondary, and, if made of uranium, which it usually is, it undergoes fission by capturing the neutrons produced by fusion. In most Teller–Ulam weapons, fission of the pusher dominates the explosion and produces radioactive fission product fallout.
The first test of this principle was the “Ivy Mike” nuclear test in 1952, conducted by the United States. In the Soviet Union, the design was known as Andrei Sakharov‘s “Third Idea“, first tested in 1955. Similar devices were developed by the United Kingdom, China, and France, though no specific code names are known for their designs
Permanent link to this article: http://www.animatedscience.co.uk/2010/the-hydrogen-bomb-teller%e2%80%93ulam
Neutron star packs two Suns’ mass in London-sized space
Like all neutron stars, the object’s matter is packed into an incredibly small space probably no bigger than the centre of a big city like London. “The typical size of a neutron star is something like 10km in radius,” said Dr Paul Demorest from the National Radio Astronomy Observatory (NRAO), Charlottesville, US. The size is easy to understand but the densitiy is much more extreme than anything we know here on Earth.
“It’s approximately the size of a city, which for an astronomical object is interesting because people can conceive of it pretty easily; and yet in that space it has the mass in this case about two times our Sun. So the size is easy to understand but the densitiy is much more extreme than anything we know here on Earth,” the study’s lead author told BBC News.
The finding is important, says Dr Demorest’s team, because it puts constraints on the type of exotic material that can form a neutron star. Such objects are thought to be the remnant cores of once giant stars that blew themselves apart at the ends of their lives. Theory holds that all atomic material not dispersed in this supernova blast collapses to form a body made up almost entirely of neutrons – the tiny particles that appear in the nuclei of many atoms. As well being fantastically compact, the cores also spin incredibly fast. This particular object, classified as PSR J1614-2230, revolves 317 times a second. It is what is termed a pulsar – so-called because it sends out lighthouse-like beams of radio waves that are seen as radio “pulses” every time they sweep over the Earth.
The observations were made using the Green Bank Telescope in West Virginia. The pulses are akin to the ticks of a clock, and the properties of stable neutron stars make for ultra-precise time-pieces. This was how the team, observing with the Green Bank Telescope in West Virginia, was able to measure the object’s mass. Because PSR J1614-2230 also circles a companion star, its pulses – as received at Earth – are disturbed by the neighbour’s gravity.
“The way it works is that as the pulses travel from the neutron star past the companion, they slow down a little bit. And how we see that on Earth is that the pulses arrive a little later than we would otherwise expect when the neutron star is lined up behind the companion,” Dr Demorest said.
The team could use this effect to calculate the masses of both bodies. The group reports a pulsar mass 1.97 times that of our Sun – significantly greater than the previous precise record of 1.67 solar masses. The result is said to put limits on the type of dense matter that can make up the cores of these bizarre objects. Some scientists had suggested exotic particles such as hyperons, kaon condensates or free quarks could exist deep inside neutron stars. But Dr Demorest and colleagues believe their observations preclude this possibility. “It’s simply that if those particles were formed, the star would get too dense and collapse into a black hole prior to this point,” the NRAO researcher said.
Permanent link to this article: http://www.animatedscience.co.uk/2010/neutron-stars-from-bbc