Jon Bell, 13 May 2012
The link to the Chemistry Subject Guide does not work any more. Kind Regards Jon Go to the page

Geoffrey Neuss, 08 May 2012
Yes - work still in progress - although there are already multiple choice tests, practicals and Aim 8/TOK/International dimension etc at both SL and HL for all these topics Go to the page

Lowell Thomson, 05 May 2012
Did I miss something about when Topics 7/17, 8/18, 9/19 and 10/20 will have their own sections? Thanks. Go to the page

Geoffrey Neuss, 15 April 2012
He was a brave man! I found a bottle in the prep room when I arrived at Atlantic College that had completely dried out. I just crossed my fingers and carefully added some water and got away with it! Go to the page

Cameron Lumsden, 12 April 2012
I recall having trouble with a synthesis in university. My prof pulled some picric acid off the shelf, pour some in the test tube and shook it with his thumb over the tube - voila - whatever it was precipitated. Go to the page

Geoffrey Neuss, 09 March 2012
Ian, Fiona is usually very good about replying but she is on holiday in Italy at the moment. I am seeing her in early April so will pass on your concerns if you have not had a reply from her by then. I don't know about David maybe he is away too at the moment. In my experience though once these reports have been published it is quite difficult to change the overall picture (as this is agreed at a level above the SAMs) but views from teachers can still affect the fine tuning. Both of the Chemistry SAMs wanted to come to the workshop in Berlin and were even prepared to pay for themselves and come in their own time to hear what teachers had to say but for some reason the IB would not allow them to attend. I'm sorry I missed you earlier this week as I ran a one day workshop on Monday at Sevenoaks on Science EEs and someone (your Deputy Head?) did come from your school. Geoff Go to the page

Ian Geldard, 07 March 2012
Hi Geoffrey, I know you were not involved in the review process but thought I'd also comment here as there may be others that were, or some that read this blog but don't look at the OCC. If I'm repeating similar points here feel free to cut and paste any answers you may have given from the OCC :) I am also in contact with Fiona Clark about these issues. She was very prompt at answering my first general queries about the nature of the review, but her responses stopped when I started to ask specific questions. Of course it could just be that she's away at the moment or busy on some other pressing matter. However, my Head of Science (I'm merely a lowly chemistry teacher) has also written to David Jones expressing similar concerns to mine. After two weeks he has yet to receive any response or acknowledgement. He has also written to the specified Biology person (Alison Davies) but has had no reply from her either (my HoD is a Biologist). I'm sure they are all very busy people and we will hear something soon. I agree that Chemistry, Biology and Physics do not have to be treated exactly the same, it is just a bit annoying that the current lack of standalone SL and HL components in the options makes it much more difficult to plan mixed classes. The review proposals do not address this issue. I'm also in agreement with the idea of abolishing options altogether. This would, in my view, be better than reducing the number of them. Either leave things as they are or do away with them entirely seems the best way. The lack of IR (and NMR) spectroscopy in either the core or AHL, which used to be in the old syllabus, does seem a bit strange. Personally I'd rather include some real chemistry, such as spectroscopy, and get rid of some of the mathematical processing, such as the propagation of uncertainty. I find many students spend far too much worrying about this in IAs rather some solid understanding of the chemistry involved. Go to the page

Geoffrey Neuss, 07 March 2012
Hi Ian, Thanks for posting this as I know you have already made several posts on the OCC. I'm not part of this curriculum review so I cannot give a definitive answer to this. It would be worth asking Fiona Clark and I will when I see her. It will make my life easier writing examination questions of equal difficulty but that is no reason for the change. Personally I have always disagreed with the IB view that Physics, Chemistry and Biology should all be treated exactly the same as they are all 'science' and yet DT and ESS and Computer Science and the new Science and Technology SL course do not have the same standardisation. We used to have options just for SL and just for HL as well as some for both in the previous programme (last exam 2008) and it did not seemt to cause problems. Maybe we should also be asking whether we should have options at all. Currently some universities are concerned that some students with HL Chemistry have no knowldege of analytical chemistry or reaction mechanisms - this of course is because they have done some of the so called 'soft options'. Go to the page

Ian Geldard, 06 March 2012
What was the reason for the reduction in number of Paper 3 options? The only result, as far as I can determine, is to make the course less flexible. An aspect which does not seem to have been addressed is the balance between SL+HL in the options. In chemistry, every option has both a SL and HL component. Yet in Biology and Physics they have some that are either SL or HL. I have to cope with mixed classes (I teach 3 classes a week SL+HL and two more HL only), this makes it extremely difficult to keep both groups in sync. It would make planning a lot easier for people in the same position as me if there was a standalone SL and/or HL topic. I'd actually rather like that in the core SL and HL as well in addition to Unit 1 and 11. Ian Go to the page

Geoffrey Neuss, 02 March 2012
Thanks for pointing this out Adam. They should all be fixed now. Geoff Go to the page

Adam Lerch, 01 March 2012
Hi, Some of your links on hormones appear to have expired. Adam Go to the page

Geoffrey Neuss, 02 December 2011
You live and teach in a great country Anuradha. Just keep your eyes open around Mumbai - there are always things that you can relate to IB chemistry in your local surroundings. It is just a question of making connections. Go to the page

Anuradha Sridhar, 02 December 2011
Great would be able to relate this to chemistry in real life.I was unaware of this being in India.Thank you Geoff for this. Go to the page

Geoffrey Neuss, 18 October 2011
OK Sean - I've left the note to moderators on the webpage above but as requested have removed it from the pdf file to give to students. In fact all pdf files are editable if you have Adobe Professional. Go to the page

sean hunt, 17 October 2011
Please can you make the pdf file editable? If not please remove the NOTE to the IB moderator at the end, thank you Go to the page

Geoffrey Neuss, 06 October 2011
Thank you for pointing this out Sibel, of course you are quite correct. I have amended the answers. One of the nice things about an online site is that mistakes can quickly be rectified. Go to the page

Sibel Altay, 03 October 2011
Percentages of isotopes should be: Br-79 = 54.50 Br-81 = 45.50 Go to the page

Geoffrey Neuss, 10 August 2011
Thanks for this Angela. It would be nice to include other good ideas and credit them to the person who shares them. I know you are at Abbey School but I do not have your e-mail address. Can you e-mail it to me at geoffn@inthinking.co.uk - thanks, Geoff Go to the page

Angela Long, 10 August 2011
I have a nice (determining Ea) Arrhenius practical that I would be happy to share - let me know how if you would like to publish on here - regards Angela Go to the page

Geoffrey Neuss, 18 July 2011
Hi Mahesh, Welcome and thank you for the kind comments. You ask an obvious question but I do not think the answer is at all obvious. Some people try to argue using ‘formal charge’ that the lone pair on the C of the cyanide ion (rather than the N) acts as the nucleophile but I am not convinced by that. Formal charge is not on our syllabus and seems very much a man-made concept based on certain assumptions which may not be true. I think it is more that our simplified bonding models are simply that – simplified – and do not account for everything. Maybe we need a new paradigm of bonding at this level to replace them? It doesn’t worry me though if I can’t answer some students’ questions (as long as I can answer most of them!) I think it is good for students to realise that there are questions which are not easy to answer – maybe it would be good one day to have a whole lesson on ‘what we don’t know about Chemistry’ rather than always focusing on what we do know. Go to the page

Mahesh Warrier, 15 July 2011
This is an excellent observation which one of many students in an earlier batch had indeed come up with. I had no answers. Could you please suggest why this is so? By the way, I enjoy reading your blog! Thanks and best regards! Go to the page

Chris Hamper, 11 July 2011
I had a Merits set (not that it did me much good) and you can actually still get hold of one on E-Bay http://cgi.ebay.co.uk/1960s-Merit-Chemistry-Set-/160615555610?pt=UK_Toys_Creative_Educational_RL&hash=item25656ee21a Go to the page

Geoffrey Neuss, 11 June 2011
To be honest John I don’t (explain to students that is) as the question seems irrelevant to a chemist (but maybe not to a biologist?). ‘Organic’ and ‘inorganic’ are just labels and some simple organic compounds such as carbon dioxide and metal cyanides have always fallen in the middle. Calcium carbonate is presumably inorganic and when heated gives off carbon dioxide so carbon dioxide is usually considered inorganic but it is a reactant in photosynthesis and a product in respiration both of which are organic processes so it could equally well be considered to be organic. If I had to explain why isocyamic acid is considered by some to be inorganic I would say that it could be thought of as a product (along with water) of the condensation reaction of two inorganic substances – ammonia and carbon dioxide. However I am also quite happy to think of it as organic as it contains carbon, hydrogen, oxygen and nitrogen! Go to the page

John McMurtry, 04 June 2011
How do you explain to students why isocyanic acid is considered inorganic? Go to the page

Geoffrey Neuss, 12 May 2011
Sorry about that Angela. It is in fact an official IB publication and the link should now work. Go to the page

Angela Long, 12 May 2011
Dear Geoff - as a school who offer curriculum choice of IB and A level we are looking at the T&L benefits and practices of the IB learner profile and I was interested to see this item on your site - I wanted to access the booklet you mention and the link dod not work - do you know of somewhere else I can access it? Many thanks Angela Go to the page

K P Indrasimhan, 25 April 2011
Indeed pampering at what cost!! Go to the page

Geoffrey Neuss, 06 March 2011
Hi Angela, It is there to download at the end of each test with the correct answers blanked out. All you will need to do is use a cork borer (see below) or something similar then place it over the student's answers to give their score. Go to the page

Angela Long, 05 March 2011
I feel slightly cheeky asking - but do you have a doc with the answers to all the Sl / HL MC questions available to download (havent found it yet - it will save me a lot of cutting and pasting time! These test are really useful as a follow after mock examinations where pupils have bene able to identify areas of MC weakness and then have a set of qns all on one topic - I love them! Go to the page

Chris Hamper, 18 February 2011
Where did this idea that we should have a special science course for students who don't go on to do science at university come from? Then why not have a special language course for students that don't go on to do language at university and and and... Go to the page

Geoffrey Neuss, 11 February 2011
I agree that some simuations are really useful. My worry is that there are plans to introduce on-line based IB courses (rather than school-based IB courses) and that much more of the practical work could become virtual rather than hands-on. Go to the page

Chris Hamper, 10 February 2011
I certainly don't like doing virtual experiments however simulations often reveal things that help us to see the way to solving a problem. have a look at my blog post "not over yet". A real observation led to a problem which the simulation helped to shine light on, the problem is not solved but now I have more to go at. Go to the page

Geoff Neuss, 07 February 2011
Hi Angela, You raise a good point. If you look at the definition in Wikipedia "A beta-lactam ring is a lactam with a heteroatomic ring structure consisting of three carbon atoms and one nitrogen atom. A lactam is a cyclic amide." then my answer is correct but if you look at the definition in the Medical Dictionary "An amide formed from amino carboxylic acids containing a keto group in a ring configuration, as seen in purines, pyrimidines, and antibiotics." then the oxygen atom should also be included. When they ask these 'draw a ring" type-questions in the IB there is usually some leeway. Certainly if I was in charge of this paper I would accept both answers. A similar problem occurs with amines - do you just include the N atom or all the three groups around it too. I'm glad you are finding the material useful. Go to the page

Angela Long, 06 February 2011
Hello there - am finding this page extremely useful - a clarification point on the worksheet where you ask the student to identify the beta-lactam ring - the answer does not include the double bond to oxygen and the oxygen atom - i though a beta lactam was a cyclic amide so should it be included or are we only asking pupils to id the heterocyclic ring part? Many thanks Go to the page

Ruth Braadley, 03 December 2010
Very useful to liven up lessons Go to the page

Julia McAllister, 30 November 2010
So much better! Can't believe your speed of response! Go to the page

Geoff Neuss, 30 November 2010
Hopefully now fixed! Go to the page

Julia McAllister, 30 November 2010
Page needs realigning Go to the page

Geoff Neuss, 30 November 2010
Fair point Phil, but actually it will have virtually no affect as the mass change will be negligible. I've added it in the blurb above though so thanks for pointing it out. In reality it is probably more accurate as less product escapes as the lid does not have to be lifted during the burning of the magnesium, whereas it does if you use a crucible. Go to the page

Phil Davison, 30 November 2010
I find cork borers make good holes in paper. Alternatively, put circles on an OHP acetate (or should we call it an ethanoate, being Chemists?) Go to the page

Phil Davison, 30 November 2010
Makre reference to the term "glacial" and its origin. Go to the page

Phil Davison, 30 November 2010
International schools may not have access to Hazcards but information can be found on the web. One source is http://msds.chem.ox.ac.uk/msds-searcher.html Go to the page

Phil Davison, 30 November 2010
Does the paint on the bottle tops burn off and affect the result? Go to the page

Phil Davison, 29 November 2010
I would consider putting lab requirements for the lab technician with each practical. Go to the page

Phil Davison, 28 November 2010
Primo Levi's book is very good. One can ask students to write equations for the reactions in the book. I have done this for the last chapter. I particularly like the chapters on potassium and carbon. Go to the page

Phil Davison, 28 November 2010
I searched and found a whole host of entertaining periodic tables, including a rude one in Spanish. I show these to my classes and we discuss them. A circular one leads to a good discussion and comparison with the one used in the IB exams. Go to the page

Geoff Neuss, 28 November 2010
I agree. It is useful for teachers who are new to the IB and also as an aid to teaching each topic but it is particularly useful when it comes to students revising(UK) or reviewing(US) their work as they prepare for their final exams. Go to the page

Rodanthea Scourtelli, 28 November 2010
This holistic approach of the syllabus is by far the best way to approach IB2 revision class-discussions and best way to consolidate how chemicals concepts interlink. Go to the page

Geoff Neuss, 06 November 2010
I agree with you Rodanthe. In fact, I would not teach the halogens until I was doing Topic 9 oxidation and reduction and I would also leave transition metals until I cover standard electrode potentials. But, remember the IB syllabus is simply a list of what students will be examined on at the end of the two years (and how according to the objectives). It is not a teaching programme and you are free to teach it (and indeed anything that is not on the syllabus) in any order you like. Go to the page

Rodanthea Scour, 05 November 2010
Franlkly speaking I have never understood why Periodicity comes before Bonding. How can one explain the trends in melting and boiling points in Groups I and VII without explaining first metallic bonding (size of ionic radius, number of delocalised valence electrons per atom)or van der Waals's forces for the changes in states in the halogens or to explain complex ion formation (ligands) without having explained dative bonding. However, it is a 'must' for one to make a start with Atomic Structure followed by Bonding. all other topics can be taught in any order. Go to the page

Rodanthea Scour, 05 November 2010
All the points raised above are very useful as they provide extra clarification on these "grey " areas. I find that unless I make reference to the Inductive effect it is a battle to explain some of the above or the SN1 mechanism. Therefore, I wonder whether it would be useful be included in the next syllabus amendment. Go to the page