Chemistry

An explosion helps

/ Mr J Dexter / Leave a comment

In my NQT year I took a 5th year class. Schools don’t like to do that, to give Y11 to a shiny new teacher, but they were short of Chemists (nothing changes). Of all my classes I worried about them most, this was an important year for them, it was their “chance” I would get other chances they wouldn’t. I prepared my lessons well BUT struggled to win them over, it would take time and time we didn’t have. They always arrived slowly, ambled in, took ages to get their books out and coats off – in fact anything to delay learning and there were always niggles – forgotten books, forgotten pens, do I have to wear these goggles? ……teachers know this scenario well.

The timetable didn’t help Friday last lesson and Monday first lesson is effectively a double split over a weekend and I soon learnt to do some practicals and demos Friday and the theory on Monday such was their attention span or lack. I did rely on the lab technician as do all science staff – these folk are unsung heroes, and Kathy was such for us. However her hours changed and she left early on a Friday but diligently left me my materials.

It was one such Friday after demonstrations of the Halogens ( GroupVII) and a class experiment with iodine solution the class left and I was happy, it had gone well after the usual shaninkins. However just as I was locking up this upstairs lab, I realised leaving even respectably small quantities of chlorine and bromine and iodine wasn’t good and no one else was clearing away. No one had told me about Hazcards, or I had already forgotten. These cards have alls sorts of info per chemical…. how to make, use dispose and treat spills or ingestion etc). Still, me a graduate chemist of a fairly prestigious University tried to recall on a Friday after a long week how to dispose of anything too risky. I seemed to think was possible to dissolve the excesses in alkali. Tentatively I did so in the fume cupboard mixing with sodium hydroxide and washing down the sink (chemists forgive me). Just as I left the lab I noticed at the back a load of tubes of Iodine water the class themselves had used to do similar tests to my demo of the other halogens. I had used up all my alkali and so without further thinking I dissolved this into another alkali and swilled down the sink on the teacher’s bench. After all iodine is much less hazardous! [PS DO NOT try this at home!]

Twas on the Monday morning they drifted in after assembly half awake and I greeted them cheerfully cleaning the blackboard with my dusty cloth and then flinging it down the bench with a little much gusto. The cloth slid gracefully into the sink and there followed an incredibly loud bang, a very sharp crack, a significant puff of smoke and a small purple cloud. Even I took cover for a moment. – whence the cloud disappeared I looked out to find not one pupil in my classroom. As I walked from the front bench I found each Y11 cowered on their knees, heads in their hands, behind their bench in total silence.

What had happened was the sink like many an old school facility didn’t drain well and some of my waste solution stayed around the rim of the drain and dried out as the water evaporated over the weekend and out crystallised probably the tiniest amount of Nitrogen tri-iodide – an explosive substance detonated as they say with the touch of a feather, it was used in those devil bangers and I suspect little cap guns when I was little.

Somewhat embarrassed I did explain this to my Head of Chemistry (my Head of Science wanted the recipe – typical Physicist) but any embarrassment was more than made up for by my class. Once they emerged from their defensive positions they worked their socks off and did so with through the year. I never made that chemistry mistake again, whether I used that disciplinary technique is another question

Lab technicians are wonderful folk but they store stuff along with storing knowledge, I learnt that day to double check and do my research carefully.

Discipline is vital in schools, good behaviour in lessons but it need not come from shouting, or serious control or deep sarcasm, or worse, persistent nagging. Preparing something interesting to learn and working hard with relationships was what I always had to do, but I did need the occasional extra hand from a head of year, a head of department or a small explosive.

[Beware, Nitrogen Triodide is a highly sensitive contact explosive, completely unpredictable and the iodine vapour a hazardous gas DO NOT try this at home or work or ….]

A slight rant over ‘Textbooks’ which I love*

/ Mr J Dexter / 1 Comment

“…a book that contains detailed information about a subject for people who are studying that subject”

1 I once wrote a Chemistry textbook – with two other great Chemistry teachers –

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Our Foundation level textbook

not examiners, not academics just plain Chemistry teachers. It was for the so-called less able or foundation GCSE pupils, labels I use but intensely dislike and I learned a lot win writing it and it was a fantastic challenge to help lots of pupils access our subject – especially those who find it hard – which is nearly everyone. It didn’t make us a fortune, schools bought lots of texts for the more able ( have a copy at home have a copy in school etc, but this was for the less able who were in small groups and often weren’t allowed to take a book home). Continue reading →

Chemistry Practicals in the new world

/ Mr J Dexter / Leave a comment

There has been an interesting debate on the MyRSC  “Talk Chemistry” and twitter and various blogs which raise an important question for the RSC, for academics teaching and designing courses for Undergraduate Chemists and for schools and teachers.

There is always change – I’m only in touch with the changes to A Level Chemistry, AS Level Chemistry, and around the corner GCSE Chemistry; the profound changes over practical work.

Universities will have changed too, new techniques, scrapping old pracs, developing new skills – I am slightly guessing at this though.

So will new and young teachers in school have the skills to deliver practical work and perhaps more broadly motivate pupils as they once had or actually need in this “new world”? Can they do a good demo? Can they deliver the organic prep the new spec demands? Have they even used the kit they find in a school under financial pressure where Chemistry puts most of its capitation down a drain? Seeing some of the nonsensical practicals suggested for AS and A or at least the slightly odd quantities will teachers (old and new) know where to turn for proper advice – CLEAPSS, RSC, ASE – sure but exactly WHERE – they are busy people?
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Is it time for the RSC to take a snapshot of practical work at UG level and bring together the skills developed in UG courses and design any necessary training courses for potential and actual teachers in secondary. What role “old hands” like me who should be able to help show how show a good demo ( patter and all) or point out the pitfalls.

Over my career of 34 years in comprehensive school classrooms – the magic, the mystery of Chemistry is delivered through a range of activity but practical activity caught me in school and I daresay caught you – is anyone making sure practical work isn’t sidelined to the side bench?

We know sometimes physics or biology colleagues struggle with doing some of our Chemistry practicals – probably easier and more comfortable to hit youtube – so Chemists let’s stand up and be counted and ensure whether it is assessed, sidelined by exam boards or rubbished – that we maintain experimental Chemistry at the heart of our lessons, our teaching and our future workforce of Chemists.

Meanwhile let’s see just what the score is!

Tuesday period 2 – #LoveChemistry, #LoveSalters’, Love Investigations

/ Mr J Dexter / 2 Comments

imageSo this post is about practical work in science, it’s not a review of the proposed changes to GCSE practical or those already in hand for A Level. It’s just my little world of practical work as a Chemistry teacher, and it is what I will be doing on Tuesday’s period 2 for a few weeks.

There are different types of practical work in science. When I used to plan on a scheme of work, we had various codes : PP pupil class practical; PD Pupils help in a demonstration.TD Teacher demonstration. AP assessed practical. I am so old that when I did my A levels we had science practical exams. In Chemistry this was usually a titration and mostly oxalate /permanganate ( ethanodioate/Manganate VII for the younger reader). We knew what to do, I had after all done one about a dozen times. We also had some analysis to do, a so called unknown and a few simple tests, flame tests and maybe some solubility tests to show this was Potassium Sulphate ( lilac flame, ppt with Barium Chloride). BUT oh how far we have come.

Let me tell you about my Yr 13 who have done practical Investigations now since 1994 and for a good few years of them I was also a moderator for Salters’ Chemistry. They have to choose their investigation, describe it including relevant chemical ideas and then plan the methods. In recent years we have had a new mark her for the difficulty and challenge of the topic, so if they choose an experiment we have done as an activity it scores low down. Modify the practical, use ideas beyond A Level and bring in a series of other skills and you might move to 4/5. Once planned we teachers have to mark the first sets of skills: planning, communicating, researching, risk assessments, references etc. The students work very hard, they score a full range of marks but maybe at the higher end of their grades. Why? Because they are A level chemists and quite good at this. However an Investigation means testing skills they don’t otherwise have

Mr Dexter at the RSC EIC 50th. School chemistry over 50 years

image Mr Dexter at the RSC EIC 50th sharing some differences between Chemistry in 1963 vs 3013 photographs from (c) Royal Society of Chemistry

So then we get going, usually three weeks of lessons and plenty of extra time. Students pop in during their free if staff allow, they come down at lunch or after school and we sometimes do a long twilight and Pizza. They start slowly in fact the first week I always wonder if they will make it but week two sees much progress and week three I see…experts! So now they have some results and observations to report ( and score) and they can analyse them (and score) and finally they do a decent job on what I usually think is the hardest area, evaluating what they have been through – scientifically evaluating that is, not a series of moans!imageBefore you say it cannot be assessed, I disagree the Salters’ mark schemes work. They work because back in the early 90’s teachers and boards worked together. They work because there were trials and developments. They work because there were good Chemistry teachers (who will remain nameless but you know who you are, ensuring marking and moderation worked.) but mostly they worked for being well designed, well thought out and because of the reactions we saw in our students ( not chemical reactions!!)
Why do I like Investigations?

  • It does feel as if this is what proper chemists and maybe research chemists actually do. A mix of researching methods, designing an investigation, carrying it out and persevering when it doesn’t quite do as it’s told.
  • We all learn lots of Chemistry, the students, the staff, the lab technicians but most of all the students. Even those who can just about understand concentration, dissolving, diluting etc get a much clearer understanding by doing it and by doing it AND being assessed.
  • The quality of work can be amazing. I recall in the early days of moderating seeing some truly wonderful investigations, given a relatively free rein it showed just what A level Chemists could do. they were ambitious, clever and often original. I even recall showing Professor David Waddington a project he diligently read it.’ What do you think?’ I hoped he would say it was ‘very interesting’ or’ innovative’, his reply: “probably worth a first”.
  • It’s one of the few bits of assessed work students enjoy. I know they also get stressed about the marks but if they plod on they usually enjoy the experience, usually do quite well and genuinely understand chemistry better.
  • They become mini experts. When we resume ‘normal work’ and revision they can teach their peers on kinetics, on errors, on calculations etc. I often turn to them ” tell us how you solved that”, explain how you worked ‘that’out.
  • It can inspire and motivate. In my day whenever did an A Level practical, let alone an assessed one, persuade me that Chemistry was exciting or innovative or frontier, though to be fair it showed me it was very useful. I have seen young people carry out their practical project and want a rethink on their HE choices. See n many of them get to grips with this fascinating subject in new ways.
  • It builds skills, all sorts from the practicalities of problem solving through to the softer skills of perseverance (though maybe if I say ‘Character building ‘ the politicians will listen). They also work on their own not in a pair or a group but independently – hey a bit like real Chemists?
  • It is perfectly assessable. Our students get a range of marks, from many 4/5 or 5/6 right down to 2 or 3/6. That’s a tribute to a good mark scheme, fairly properly applied, internally moderated and externally moderated. Practical work vital to my subject, should and can be assessed.
  • The hardest aspect back in the early days was researching ideas and practicals, it so often depended on getting the right books or articles, but what a great opportunity to raid the ASE and RSC cupboards. Now of course we can go on the internet. AND sure I know that’s why some people feel the whole of practical work can be cheating but really – have you ever met Chemicals?
  • No one gets a practice. You can’t do a four week project twice, you can’t rehearse, you can’t spend weeks researching and planning and then change your mind. It’s a good test!

imageAnd if Investigations ( let alone practical work) disappear?

I, for one , will be sad, I can’t think any other assessment building skills, showing off Chemistry, motivating and contributing to the student learning experience. ( although I do know learning for an ordinary test or exam does concentrate the mind). Maybe we can still do them, say the end of Y12 (Oh No) the skills won’t be quite so well developed and hey the AS is gone or going or something. Maybe we can do a mini project (Oh No)– you need four weeks, is there really that much spare time or are we refilled with extra content in the new world? Maybe there is after school, the Chemistry club – Oh No – how disappointing that something which should be done in lessons is reduced to ‘after school’ or ‘ in the holidays’.

If you are an examiner, assesor, moderator reading this, don’t worry we Chemistry teachers will make whatever yuou give us work, its what we do, but me, I am still allowed to mourn.

I never did an Investigation when I was at school, and it never did me any harm. I didn’t do one in my three years as an undergraduate maybe that didn’t do me any harm, but I did a part II whole year of research which I adored. That was back in the day without the resources we have now, I think I’ll just be that sad old Chemistry teacher…..”oh in my day”

My plea, please don’t throw out the baby with the waterbathimage

You might like to read other posts from my timetable of teaching – each is set out from lesson in the school week, before or after school or at the weekends, appropriate to the time of day. I have also started a  class lists or “set lists” which was to answer the questions: “why be a teacher?”or “why have other responsibilities in a school?” Shortly I am starting a new area about progress from one role or experience in teaching to another with hints and tips about successfully moving on in the job and your teaching career.

 

7 YBA Chemistry Teacher

/ Mr J Dexter / 1 Comment

In my blog yba teacher I confess to a small white lie or being economic with the truth – teaching is a great job but Chemistry teaching is the best!

[Now I know there are frustrations, problems, annoyances, SLT (hey I’m one) BUT here are my positive thoughts.]

What it is about Chemistry and teachers?  It’s a great subject to teach, though not easy (are any?) so what do I think makes our subject unique , intriguing and beguiling.

It has a great intellectual capacity and challenge. There is no doubt there is a lot to know, a lot to understand, a great deal to work out,  a challenge of how it all applies but at its most basic Chemistry is about ‘problem solving’. From the exam questions to the global problems and from the latter the history of discovery, serendipity, heroes and well a few anti-heroes too, some absolutely lifechanging discoveries and developments and some we are overwhelmingly embarrassed about. but it generates huge curiosity. One of my first ever lessons with a brand new shiny y7 and I added acid to indicator, then added alkali and as it went from red back to green a small child open-mouthed, staring from a silent audience in my lab said “bl**dy hell that’s amazing” and the whole class and me gasped, his face said it all, one of astonishment and yes we had a word about his words. but who couldn’t read about our subject and not be curious. There are patterns and themes and exceptions and rules and maths and observation and theory and practice, what could be more intriguing?

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For me the real highlight is that it has great stories : of discovery, of changing the world for the better, of poison and intrigue, of dedication, of enviable cleverness, of battling against the odds. Stories of people (too many to list) and materials. it has a great history, it’s involved in culture, it is …everywhere. If you are a non chemist reading this get hold of ‘Chemistry world’ from the RSC in a local library and I defy you to read two or three copies and still not agree: medicines, dyes and paints, fuel, energy, food, agriculture, materials from plastics to metals, detergents, cosmetics, …..just soooo wonderful. I might even claim the history of mankind is driven by Chemistry, you can’t fight a battle against warring invaders in a bronze age without..bronze, and you can’t fly aeroplanes to escape without Aluminium. I can only tease you here, otherwise it’s a book on the way!

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Resources: the subject has come along way in classrooms since I learnt in the 70’s from a textbook and the occasional copy of “New Scientist”. There are fantastic books and blogs, magazines and great stuff for children like the wonderful “Chemical Chaos” We have great writers like John Emsley, how could you read anything he has written without being desperate to share the story. But it creeps in elsewhere in Physics and Biology from DNA to solar panels…we are here, there everywhere –  #loveChemistry. I have taught Salters’ Chemistry since it was first piloted in the 1990’s but if you don’t teach it, get the Chemical story book and I’ll refund your money if you don’t make good use of it

People: The subject is a living one and so we study past, present and future at school and then there are graduates, PhD’s  and post docs, researchers and professors, retired Chemists who blog and write and tweet, there are Uni researchers sharing their research. Check out the RSC Learn Chemistry  and make sure your school is involved. If you are not on twitter get started, and follow the likes of…actually it’s not fair to mention a few here, there are so many keen to help and half the fun is finding them on twitter, some may even retweet this blog. In due course I might get around to listing the bloggers and tweeters. Alternatively search for #Chemistry or #lovechemistry. There are also the phenomenon that are twitter chats such as #asechat. Over my 30+ years I have had the great genuine pleasure of meeting all sorts of academics, industrialists and educators. They have always been willing to share and help and support. I’m not sure I have capitalised on this but it can be done. My school had a wonderful industrial link with Boots locally for many years when industrial visits were part of the specification – Boots were hugely helpful and my students found the visits to….essentially pipes and pots…fascinating. How? The whole visit was around solving problems in production of Ibuprofen and hey….they were good. [see ofqual there is more to teaching than assessment ut your is a critical role!]

Web based resources. In recent years we have seen a growth in resources on school websites and university websites and fantastic links to be pursued and followed. Organisations well preeminently the RSC but also the ASE. Local sections, paid staff and volunteers, publications and websites and the most wonderful CPD.There are foundations like Nuffield, organisations like CIEC, NSLC and University departments too numerous to mention, my experience is that these people are always willing to respond and support too and I’ll add in any more if you let me know any obvious one’s omitted. I have though to mention @RSC_Eic because their website and magasine has a special place in my work but it is always an inspiring read with something to make you think and something for you to try and use. stuff for students, events to take students along to and great ideas to use with them. I can’t leave this section without referring to videos ( hey we watched the Christmas lectures in my day) and of course youtube has great links. You really must store periodic table videos from the University of Nottingham in your favourites but here is my all time favourite video all the way from 1947.

Practicals: From demonstration to class practicals through to investigations. I still love demo’s, yes a few bangs and a few ‘ooh agh’ colour changes or explosions but also the finer details, demonstrating a titration properly and seeing youngsters learn and do their own, aiming for really good results. Class practicals, especially if we keep them a little open ended and coax some extra curiosity. No not those we have to use in coursework or controlled assessments, just great practicals. If you get a chance make use of local companies or Universities willing to show/use some of their big kit too. I am still scared when we start our Investigations with Y13. Perhaps ten or twelve different experiments over 3 weeks, carefully planned, executed only to find this is Chemistry and sometimes doesn’t do as it should, written up, analysed and evaluated and all that for 90 UMS, and they enjoyed it. Not sure where this is going in future Ofqual!

Making nylon

Exam questions ( well applying Chemistry) I mentioned intellectual curiosity and once pupils have learnt enough basics ( although my University tutor claimed that took 3 years as an undergraduate) we can then solve problems. I refer readers to OCR specification assessment materials, they are a major challenge as pupils look at their problem solving in a new context. All the exam boards have stuff like this. You can’t really look at solutions to an ozone crisis without understanding bond energy. You can’t look at fuel replacements without a deep knowledge of thermodynamics and despite the interest in a manufacturing process you really do need to get a good grasp of equilibrium and kinetic Chemistry. I recall one bright A Level student say to me after their exam “Sir that was really hard, you never taught us about poisoning deer” which was true, the derivation of course was Arsenic chemistry (also not taught but worked from the pattern of N and P). I love those new and different contexts and I always reckon one of these young pupils might just be able to replicate photosynthesis in a test tube one day.

Frontier stuff: Yes we can share the here and now, sure we have to cover atomic models established back at the turn of the last Century but we can look at the major modern progressive stuff too:green chemistry or clean technology, computer modelling and yes we can read about whoever won the Nobel Prizewinners in Chemistry (another brilliant website) and we can think why and what it might mean.

Chemical education research it’s not just a subject with diverse, interesting and challenging content from the worlds of Industry, academia, research, Art, culture. But we do have proper chemical educational research, and like the content it’s not just a UK tradition. if you need a starter, try this site, but do look at stuff going on in Higher Education too as much can be brought down into secondary.for example there is a lot of discussion going on about ‘flipped classrooms’ bet we can draw from that. ( oh and they might learn a bit from us too). So lots of wonder CPD and commitment, including the RSC’s latest paper on Chemistry teaching and I added a positive but challenging voice in a recent endpoint, whatever happens the commitment is there for the profession.

Rare orchid, smells of chocolate, makes the milk of cows that eat it turn blue!

Rare Swiss orchid, smells of chocolate, makes the milk of cows that eat it turn blue.

Activities  Pupils do love their practicals but we are richly blessed, we can stimulate great data analysis, we can develop and try out micro scale practicals, we can turn to molecular and computer modelling. Back in the day I tried so hard to think in 3D and I think my inability prevented my progress but then along comes molymod models and then computer graphics. This will light up the Chemical world. I have a few old OHP I drew to explain electrolysis, atoms with a bit missing (cations) and atoms with a little extra electron being picked up and I flashed these up quickly to make a video. Laughable now as we can see so many animations, we can even do ‘play’ experiments in school altering the temperature and pressure etc of complex reactions or processes.

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Ah – the Element of surprise

Careers– I think Chemistry qualifications show some sort of standard even in this ever changing time. Our pupils are well served by a GCSE in Chemistry, an AS or A level and BTec’s in linked areas ( though I wish the vocationals could be sorted properly!) and of course a massive variety of degrees and linked degrees. But we chemistry teachers can get great careers too, after all these teachers are good problem solvers ( theoretical and practical) they are good communicators, they know about research principles and hopefully they are a touch eccentric and they share great good humour: need I say more! Interestingly the fantastic Chemistry teachers I have met and worked with, very often still think of their classroom lessons as the highlight, they really do #lovechemistry.

Colleagues – I work with and have always worked with great chemistry colleagues, sharing ideas, learning from each other, thinking how to improve what we do or frankly working out how to use some new spec or new assessment model to advantage. Just discussing Chemistry with another person interested in the world of Chemistry, is frequently uplifting.

Students– best bit of the job, trying to teach them, trying to help them learn, coping with their lows and highs, getting them through mocks, tests, exams, answering their questions, moving their ideas, challenging their understanding, helping them solve problems, sharing the stories, working out how to motivate this one, challenge that one and support them all. The best being when they get it, when the proverbial penny drops, when they see the bigger picture. The other reward when they enjoy chemistry, decide to choose it into y12 or y13 or HE. Especially those having chosen it as a ‘ best of a bad choice’ who find they too #love chemistry and then think of HE or employment in the world of Chemistry. Seeing them sailing off into the Chemistry sunset….or sunrise 🙂

So if you are a prospective chemist wondering about teaching at school or in HE…go for it, you won’t regret it, and if you are a Chemistry teacher in the broadest sense:

Q1 What else do you think makes it a great subject?

Q2 Are there other things professional bodies could do to help us?

Q3 What obstacles that stand in the way do we need to shift?

Q4 How else can we share our enthusiasms?

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