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Talk:Organic Chemistry

Hello all! I'm a newbie to this WikiBooks thing. However, I've been thinking about contributing to this book for a long time, as I feel I could at the very least help organize it. I believe that, although there is a decent amount of information shoved in, this book still has a long way to go... I would actually qualify it as more at the 25% status than its current 50% status, relative to other books. But, more importantly, is anyone still here? It seems that all edits/revisions are at least 3 years old. TheFleegsLeegs (discuss • contribs) 18:03, 10 February 2019 (UTC)

Hi! I just reviewed your book, updating your development stages. Wow! This took some time, cause it is really a BIG book with many many sub-chapters! I was impressed by the quality and clear style of writing. Keep up the work, and concentrate on the 75% chapters: I think many of them can be 100% by just finishing up the pages or including those examples that have been announced, but obviously forgotten... (See Help:Development stages for how to use this template, and if you read this, help by reviewing another book and spreading the word! Thanks!) --Andreas Ipp 23:30, 12 Jan 2005 (UTC)

I'll work on this again in the fall when I'm in the mood for organic again --Ghostal 23:00 EST, Apr 11, 2005

In module Ketones and aldehydes
I suggest that the topic "Preparing Aldehydes and Ketones" should have subtopics of "Preparing Aldehydes" and "Preparing Ketones". Not all of the preparation methods can be used in both instances. It would help with clarity. Glich (talk)

New icons
I have uploaded to the Commons two pictographs that I made: , . They are both public domain. Ramir 13:19, 31 May 2005 (UTC)

Official Headers / Footers
Hello all! This is an amazing book so far, and I look forward to editing it. I'm curious which pages include the 'official' Header and Footer (including the little ethane icon). I'd be happy to standardize as many as I can, but I need to know which you prefer for the standard.

Cheers! Buxtor 22:44, 2 June 2005 (UTC)

Standard Structure Format?
Hey All! There's really quite an impressive array of work here. I'm concerned, though, that there's no nice standard way to display chemical structures. While we don't have the same engine as the math guys do for displaying sturucture like they do equations, we can still try and settle on one program and settings for making structures, no? I'd recommend Chemdraw, ACS template with the bold width 2.5 and line width 1.5. --Lineweaver 08:46, 23 December 2005 (UTC)

Naming policy
Great work you are doing here. However I must suggest you have a look at the Naming policy.

--Krischik T 07:55, 16 January 2006 (UTC)

 * Indeed, I shall berenaming all pages in this book so that they start with "Organic Chemistry/". This will make this book consistent with most other wikibooks, plus allow for easier navigation. I trust this change will be non-controversial (especially as it is being done in a way that preserves all links), Jguk 12:41, 20 February 2006 (UTC)

Print Version of this Wikibook
If you look at Organic Chemistry/Print Version, I've put together a compilation of most of the pages for this Wikibook. I have excluded pages that have not been created yet (so if you add new pages, it might be good to put them here), and I'm still working on the appendix sections.

Feel free to edit and work on this print version, but it is looking pretty nice at the moment. Don't worry about keeping the content up to date, as if you work on adding just content to the existing parts of this Wikibook it will also be updated in the print version automatically. This is done through the transclusion process. Some minor reorganization may have to be done with the various sections, and there is some duplication of a few items that still needs to be dealt with.

Anyway, have fun with this content. BTW, I'm preparing to make a PDF version of the print version, but it would also be nice to clean up the content before we make this "official". There are far too many red linked images, and I'm not sure exactly what happened here to make them red links. I can't find any history of those images from the deletion log. --Rob Horning 17:49, 13 March 2006 (UTC)

A page move
I've started doing work on the Substitution Reactions page, but I'd like to rename the page, Nucleophilic Substitution Reactions because it's a little more accurate as well as being more descriptive. I assume this is done simply by "moving" the page. Being new at this, however, I'm reluctant to make such a change without someone saying "go ahead and do it." I read the noob stuff and it said, "be bold", but I'm drawing the line at moving a page, for the moment. --Pete 15:25, 11 November 2006 (UTC)

Duplication
The Haloalkanes page has a short section on reaction mechanisms that duplicates a lot of what is discussed (and in some cases, contradicts) in Substitution Reactions. I haven't yet gotten to the Elimination reactions page, so I don't know if there are contradictions there, but there is surely some duplication.

It's probably best to link to the Substitution Reactions and Elimination pages from Haloalkanes and move whatever is needed from the Haloalkanes page.

As for contradictions, the first thing that caught my eye (since I was updating this in the SN2 reaction mechanism, is that in the Haloalkanes page, it says non-polar solvents are preferred. This is, as far as I know, incorrect. Aprotic polar solvents are preferred in SN2 reactions based on nearly every book and online source I have checked. Pete 19:56, 11 November 2006 (UTC)

Some reorganizations
Okay, I've moved some stuff around a bit. I've tried to be really careful to fix all links so that they're not going to redirects or blank pages, but I have no doubt I missed something somewhere. This turned out to be a MUCH bigger project than I expected it to be.

Basically, I renamed (via a move) Alkanes and Cycloalkanes to simply Alkanes. It still has a short section on Cycloalkanes and some of this will be left there and maybe some minor changes made because it's a very short introduction to cycloalkanes.

I will add in a new section entirely on cycloalkanes, after the stereochemistry stuff which will go into much greater depth about cycloalkanes.

And the small move was Substitution Reactions was moved to Nucleophilic Substitution Reactions since that is what it was and shouldn't be confused with other types of substitution reactions.

Standard chapter structure?
Should we have a standard format for each chapter? I usually go for:

1: Methods of making this class of compound (often referring to section (3) of other chapters)

2: Properties of this class of compound (including nomenclature, uses, etc)

3: Reactions of this class of compound (often leading to section (1) of other chapters)

Ewen 10:48, 20 November 2006 (UTC)

 * Ewen, yeah, I think that makes a lot of sense. I assume you mean the chapters for each functional group.

 * Yup! Ewen 14:40, 20 November 2006 (UTC)

 * I haven't decided how I want to do it, but I want to bring the Nucleophilic Substitution and Elimination reactions stuff into an earlier place in the book, possibly in their own section. I'm also not happy with all those reactions being in the back of the book. Reactions should generally be with the class of compound they're with. If a reaction has been covered previously for another functional group, you just don't need to go into any depth about mechanism, as that will be covered the first time it comes up. -- Pete 14:20, 20 November 2006 (UTC)

 * I agree. I'd prefer that when a reaction type first occurs that it has its own section, so that it can be found more easily later. I'd prefer that to the reaction type being a sub-heading of some or other functional group chapter. Ewen 14:40, 20 November 2006 (UTC)

 * Precisely and I think this is how most books handle it. I mean, you go read a chapter on carboxylic acids, and in every books I think I've seen, there's a section (or actually, usually multiple sections) dealing with all the reactions related to creating carboxylic acids and reactions that carboxylic acids can take part in. Frequently, the first time that particular type of reaction is shown and it's important, the mechanism is usually laid out with electron pushing, transition states and/or intermediates... I think we need to do all that stuff. I'm all for trying new stuff, but I think the reason it's laid out in most books this way is because it makes sense to lay it out this way. -- Pete 16:30, 20 November 2006 (UTC)

 * As an additional note, I think we ought to move Alkenes and Alkynes an place them between Haloalkanes and alcohols. I think they should be discussed before alcoholis and I think Alkenes is probably the place to begin discussing reactions and reaction mechanisms, not haloalkanes. My reasoning on this is that haloalkanes are often used for creating different functional groups. For example, dehydrohalogenation to create an alkene. I mean, we might want to discuss halogenation of alkanes in the haloalkanes section, but I think that's probably the only thing. It's not a particularly useful reaction since it produces so many products, but that's really the only one I think would be useful there since most of the other reactions involving haloalkanes result in the creation of different functional groups that are discussed later. Anyway, just a thought. -- Pete 16:36, 20 November 2006 (UTC)

 * Ewen, on a related note, in regards to structure, if you look at, for example, the Alkene chapter, notice how you go to the alkene page and it simply has links to other pages. I think this is a bad way to do it. Then if you go to Haloalkanes, it's all one one page. I think having it all on one page is the better way to do it. I think for Alkenes and Alkynes and other chapters that might be laid out that way, we ought to take the information from the sub-pages and merge it into the main page.

 * There are alsos some things there that need reorganization. Alkenes, for example, has a section on pi bonds. Pi bonds ought to be covered in the Foundations section along with other bonding stuff. I mean, Pi bonds are certainly worth mentioning elsewhere since they play a huge role, but I think they should be introduced before Alkenes. What are your thoughts? -- Pete 20:36, 20 November 2006 (UTC)

 * Yup! Haloalkanes seems the way to go for structure. What sort of page length are we looking at before splitting them? Pi (and other) bonding is surely fundamental rather than a passing topic of relevance mainly to alkenes. I'll have a bash at some of these issues. I work in a different time zone to you don't I? We'll not have edit conflicts unless I stay up late or you get up very early 8-) Ewen 20:52, 20 November 2006 (UTC)

Wow, you've been busy today Ewen. I love what you've done with the Alkanes section... We might step on each other from time to time. I work from home and I sometimes get a little work in on the book during my lunch hour or something. I don't think there's too much danger, though. I'll be doing most of my work in the evenings and weekends, so the 6 hour (maybe 7) time difference should keep us from stepping on each other too often.

I've deicded I'm going to keep away from doing any big moves for a short while. I did that pretty big move of the Alkanes section over the weekend and it turned into a much bigger job than I expected (because of all the links that needed updating) and I just kinda bit off more than I think I was ready for, so I'm going to slow down a bit. I've also almost made some structural changes that I would have regretted because I didn't see some other stuff that was going on.

So, with that in mind, for a week or two, I'm just going to do additions here and there around the book, maybe a little cleanup, and just make sure I have a better feel for where everything is and how it's laid out, what's missing, what's duplicated, etc, and adding it to my To-Do List. I'm also going to try to wrap up some of the stuff I've started, like the Cycloalkanes stuff and I need to do some more work on Elimination and Nucleophilic Substitution, and then bring them together in Haloalkanes, I think. It definitely makes sense to discuss Nucleophilic Substitution and Elimination together, if for no other reason, than because they have a tendency to compete with each other and it's easier to address that with them together than it is to address it in each one separately. Anyway, just trying to give you a heads up on where I'm going, but I don't see us bumping heads too much in the near future... -- Pete 22:46, 21 November 2006 (UTC)

Chapter structure
Ewen, you originally proposed chapter layout made sense at the time, but in working on the Alkene section, I ran into problems with it. I think what we ought to do is put together a layout model somewhere off of the Outline page and then we'll use that as a basic layout model for all the chapters that are based on functional groups. Here's the problem I ran into. I was writing about the synthesis of alkenes and for dehydrohalogenation, it goes by the E2 mechanism and thus is regioselective and, depending on the alkane, can produce reliably consistent products or possibly a mix of E and Z product. The problem is, the E and Z naming isn't discussed until later in the section, which made me stop in my tracks and come here. I think we ought to consider an order like this: Properties is sort of a catch-all for everything not falling into the other two categories. Under reactions, we'd begin with synthesis reactions, followed by the rest of the reactions. But at least, at the point that you're discussing synthesis, you can name the products without there being confusion as to what the names mean. I'm also trying to cover reaction mechanisms with the reactions, as much as possible. But like I said, I think we ought to come up with a model chapter. Look around at other chapters and see if maybe there are specific things that we're not considering for these 3 categories. Maybe there should be other categories that aren't coming to mind right now. But we can then use that model as the basis for all the functional group chapters. -- Pete 03:43, 23 November 2006 (UTC)
 * 1) Naming
 * 2) Properties
 * 3) Reactions

 * Yes, I was thinking that too. The structure doesn't fit well with some chapters. I should have been more flexible and not imposed a structure that didn't really fit. Live and learn! Perhaps the default structure should look like this anyhow:

 * Introductory paragraph (no heading - puts it above the contents)
 * Naming
 * Possible structures
 * Properties
 * Physical properties (e.g. boiling point)
 * Chemical properties (e.g. acidity, toxicity)
 * Reactions
 * Synthesis
 * (other reactions)

 * I'm keen to list the details of synthesis reactions under their respective reactants. Haloalkanes, for example, might have a short reference to substitution of alcohols, but the main discussion is under reactions of alcohols and the haloalkanes chapter might merely reference the alcohol reaction section.

 * One advantage of this moving stuff around: It helps to tidy things up! There are so many sections where work is duplicated and written to very different standards. Finding one home for each section has brought them together and made the best of them all, or highlighted the need for someone to fill a gap. Ewen 06:40, 23 November 2006 (UTC)

 * Ewen, I think this new order makes more sense. As for reactions, I think it's okay to mention them more than once. For example, the Wittig synthesis of Alkenes, I'm going to show the reaction and write a short paragraph about it in Alkenes, but it's a reaction between an aldehyde or ketone and a triphenylphosphonium ylide. So I'm thinking, the earliest it should be discussed in detail (i.e. mechanism details) is maybe aldehydes and ketones. So, to that degree, I don't mind duplication, as long as say, the Nucleophilic Substitution and Elimination reaction mechanisms aren't covered completely in both Alkenes and Alcohols, for example. Some reactions apply to multiple functional groups and deserve at least some mention with each of those functional groups, but the degree of duplication that's been in some places is way too much.
 * Today is the Thanksgiving holiday here in the States, so I won't be doing much here. I'm heading off to visit my family for the traditional turkey feast and offer thanks to the native Americans for letting us steal their land and virtually wipe them out. -- Pete 13:47, 23 November 2006 (UTC)

 * Ewen, another thing we've forgotten is problems. Currently, there are very few problem exercises for the reader to work on. For me, this is really a low priority, but we ought to consider how they should be placed in the book. I was thinking the best way would probably be to have them as links at the end of each chapter. There would be two links: A link to the problems and a link to the answers, hopefully with explanations where appropriate. My thinking is there ought to be about 50 problems per chapter. That's a lot of work in itself, but like I said, it's low on my priorities. There are so many other things that still need work. But I didn't want it to slip through the cracks. I've added it to the to-do list. -- Pete 03:26, 25 November 2006 (UTC)

Ethers
I noticed that ethers are discussed in the module about alcohols. Might it be better to move them into a module of their own? That way, readers might be able to find them more easily. I personally would not think to look for ethers under the topic of alcohols. -- WilliamJenkins09 04:25, 28 January 2007 (UTC)

 * Good idea! Alternatively, we could rename 'Alcohols' as 'Alcohols and ethers'. Certainly ethers deserve a mention in the contents. Ewen 08:40, 28 January 2007 (UTC)

Index
Anybody know how we could add an index to the book? Ewen 08:40, 28 January 2007 (UTC)

An outdated and copycat organisation
Why on Earth has this book been organised by functional groups? It should be organised by reaction types and mechanisms, the true basis of organisation in organic chemistry. A functional group organisation belongs to the barbaric ages when terms such as electron density and carbocation stability were unknown. Such an organisation is a very poor effort in the twenty-first century.

Also, the book is seriously lacking in comprehensiveness. Only classically important topics are included, at the expense of overwhelmingly important modern topics such as orbital symmetry rules (pericyclic reactions), borderline mechanism in solvolysis, retrosynthetic analysis, chiral synthesis, basic organometallic chemistry etc. Physical chemistry is oversimplified. For example, entropy-controlled catalysts so important in biological systems are never discussed. In fact the whole process of kinetics is misrepresented, as is the difference and relation between rate and equilibrium (that is, equilibrium thermodynamics and kinetics).

Many experimental observations are left unexplained, such as why certain reactions proceed only at certain temperatures at the presence of a certain concentration of a certain catalyst. Catalytic mechanisms are rarely given. Overall, the book in its current form continues the long-observed tradition in chemistry textbooks of emphasising rote memorisation over logical analysis and understanding. The book is in need of major overhaul and a complete change in the organisation and outlook to make it into a truly modern organic chemistry text that actually enriches wikibooks instead of simply rehashing material from commonly available high-school texts. 59.93.198.128 08:53, 29 January 2007 (UTC)

 * To take your last point first: 'High-school texts' are not 'commonly available' if you can't afford them, and the scope of this book is beyond high school anyway.

 * We've discussed the organisation and the consensus seems to be that organising according to functional groups (the 'nouns' of organic chemistry, as it were) is preferable to organisation by reaction types (the 'verbs'). Why? It's the status quo.

 * Perhaps the reaction types and mechanisms organisation can be included by cross-referencing the relevant sections in the various chapters. Please go ahead and add such cross-referencing.

 * Your second paragraph asks about the comprehensiveness of the content: Feel free to add what you think is missing!

 * Ewen 10:47, 29 January 2007 (UTC)

 * Regular access to an internet connection and a computer is not more affordable than a low price edition or second hand version of a standard text. Also, in its current form the book is written exactly at the level of Indian high-school OChem curricula (though US curricula is probably more elementary).

 * Cross-referencing can not be a substitute for organisation. Where did this discussion about organisation take place? It should be reopened. It does not make sense to use functional groups rather than mechanisms, as it is mechanisms that unite OChem into a cohesive whole. Use of functional groups creates the impression that OChem is simply about memorising seemingly unconnected mechanisms of reactions of many different functional groups. I quote a professor below:

 * "...overall the books are criminally incoherent, much due to that substance classes rather than reaction classes form the "basis" of the chapter division [note: NOT "...the basis of the 'organization'...", since organization can only exist when the reaction classes are the basis for the discussions, the one thing that brings order to organic chemistry!]; never does anyone take a more "holistic" or just "passioned" view, to actually demonstrate the monumental versatility of the concepts discussed - and exactly the same highly vital information is left out, about how to interpret or control all the hundreds of written consecutive equillibria, or what difference it makes to use the methoxide rather than the ethoxide, or why 70% phosphoric acid is used (or, indeed, what is meant by 70%), or why precisely 780K and not 775Kis needed, or how you actually carry out a single reaction and what apparatus should be used, or how you handle and isolate the substances; or how you name those compounds that show up later than the first few chapters (when all the authors suddenly forget the previous efforts of showing completeness in presentation)."
 * 59.93.201.127 18:26, 30 January 2007 (UTC)

 * I do appreciate your criticisms are well-intentioned and constructive.

 * If you have a problem with the content - why not write some? No amount of requests will give me, or anyone else, more time to write material. Why not use your time to add to this book instead of criticising it? You obviously have spent some time reading the book and considering its failings.

 * If you missed the foreword then you may have missed some of the rationale - the intention is to supersede expensive college-level texts. You're right about the cost of computing or internet access, but this book also has a printable version - it would cost no more than the printing costs to make a copy.

 * Your suggestion for organisation is novel and interesting (thanks for proposing and explaining it), but I'm not persuaded that it's substantially better than the system we use now. I didn't use the analogy of verbs and nouns lightly: You need both to learn a language, but vocabulary is more important than grammar (to change the analogy slightly). How can we discuss the chemical reactions before we can name the chemicals and know their physical properties?

 * You're right, though - I can't find any formal discussion of the organisation. Pete and I discussed whether the structure should be flatter or deeper but nobody, to my knowledge, has suggested reorganising along the lines you suggest.

 * Would you like to register and choose a username? I find it a bit odd writing to an IP address! You'd also be able to add pages like this to your 'watch' list which helps discussions.

 * Regards, Ewen 19:39, 30 January 2007 (UTC)

 * It takes significantly more money to print all these pages instead of buying the book. But irrespective of whether this book replaces or supplements standard texts,I think nobody will like it to become a copy of content that is already available.

 * As for the organisation, if the goal was to discuss nomenclature and physical properties then the best organisation would undoubtably have been functional groups. But I think you will agree that the principal objective of a general introductory OChem text is to discuss reactions, and it is here that the advantage of a mechanistic discussion arises.

 * Arranged by functional groups, the conversion of a halide and an alcohol into nitriles become different things, when in reality they are the same reaction, nucleophilic substitution. This separation gives a student the idea that the only way to get through OChem is to memorise the countless reaction mechanisms separately for each different class of compounds, when he would have a far easier time if only he understood that there are only a handful of basic reactions in introductory OChem and that which one occurs can be predicted (not memorised) from a knowledge of general principles and reaction conditions. Elimination of water and elimination of hydrohalide is the same reaction, but since one involves alcohol and the other halogen a student is forced to learn them separately, adding to his burden.

 * As for functional groups being status quo, fashion can not be the foundation of science. Writing a textbook is not less important an exercise than writing a paper, and the same principles apply. Also, this status quo is increasingly being broken and most important second level OChem texts like March, Carey and Sykes have for a very long time used reaction types as their basis of organisation. It seems meaningless to deprive beginning students from what is already considered best for their seniors. Writing a good and original textbook that not simply a conventionally-organised collage from existing textbooks with sudden and inexplicable emphasis on the author's personal interests is a difficult and time-consuming task for which I don't have the time. However this labour can be significantly lessened by the collaboration offered by a wiki system, but that first requires consensus. 59.93.162.4 07:13, 31 January 2007 (UTC)

 * I hope you don't me breaking your issues into some sections and deal with each in turn? Ewen 08:54, 31 January 2007 (UTC)

Organisation
Re: 59.93.162.4's comments on organisation:

Bluntly; I don't think this book will be reorganised along reaction lines unless somebody has a huge amount of time to do it. I'm not sure that the majority of readers and writers would want this to happen anyway. It's my impression, but the 'consensus' seems to be to organise the book on functional group lines. Of course you're right; progress can be stymied by consensus and the status quo, but some projects develop by evolution, not revolution. Help in evolving the project is appreciated.

I think you exaggerate the problem. We have a section on reaction types - I gues sit needs expanding and re-emphasising. We also organise reactions from the viewpoint of the products, not the reactants. You say that "Elimination of water and elimination of hydrohalide is the same reaction, but since one involves alcohol and the other halogen a student is forced to learn them separately, adding to his burden." but in fact both reactions form alkenes, and so the reactions are also dealt with in the alkene chapter. Similary, it is not exaclty the case that "the conversion of a halide and an alcohol into nitriles become different things" because both reactions come under nitriles too.

Thankyou for highlighting the problem: By organising along the lines of functional groups we have fragmented discussion of reaction types. I think all editors of this book should be conscious of this issue and ensure that common reaction types are cross-referenced as much as possible; and that the appendix on reaction types should be used to draw these common threads together as much as possible.

Ewen 08:54, 31 January 2007 (UTC)

 * Please see comments in new section below, I would like to contribute. Le Prof  Leprof 7272 (discuss • contribs) 15:20, 15 May 2014 (UTC)

Content
Re: 59.93.162.4's comments on content:

"Writing a good and original textbook that not simply a conventionally-organised collage from existing textbooks with sudden and inexplicable emphasis on the author's personal interests is a difficult and time-consuming task"

Agreed, and the wiki system is a way to share this task. However, this is an ambitious project and it is a work-in-progress. If some sections are currently further developed than others, and these sections are the result of one or other author's personal enthusiasms and interests, then is that so surprising? Eventually, the gaps will be filled (we hope).

You have identified many areas you consider under-developed. Do please dive in and develop them!

Ewen 08:54, 31 January 2007 (UTC)

Cost
Re: 59.93.162.4's comments on cost:

The aim of the book is to make it as comprehensive and up-to-date as can be, with constant revisions. The competition would be the books listed on the Main Page, which are more expensive than the wikibook. Of course, you could buy an inferior book or on old copy of a good one; but the quality of this wikibook should justify its limited cost. We're not there yet; but already for the many students who have free internet access through their colleges the cost of this book cannot be beaten.

Ewen 08:54, 31 January 2007 (UTC)

Would like to contribute

 * I would like to contribute at this site. I am a scholarly chemical professional. However, to do so I would have three prerequisites.

I also believe that one person should emerge as a senior editor on the project, to mediate issues that might arise, and, more importantly, to review text to create a scientifically stylistically consistent final product. More on this hope/expectation, later. Le Prof Leprof 7272 (discuss • contribs) 15:37, 15 May 2014 (UTC)
 * First, there would have to be an agreed upon outline of the material that will appear, understanding that this will maintain some flexibility as the writing proceeds. The outline should seek to be consistent across Wikipedia-related venues. People who collaborate, seriously, in scientific textbook writing do so after early agreeing upon an outline to follow. For instance, I am now working on an outline for the Wikipedia ochem article, to guide a major reedit, amalgamating the Clayden text's approach, with the William Reusch msu.edu Virtual Textbook of Organic Chemistry, and 1-2 of the key American textbooks. Where is the comparable discussion here, about the goal of this textbook writing effort?
 * Second, since there does not appear to be the requirement or conviction to source the information appearing here, and since Wikipedia demands no credentials of participants, there would have to be an agreed upon set of sources, and discussion about how these would be prioritised when there are discrepancies. (Anyone teaching ochem knows that there are mistakes in published texts, some gross and some subtle, and there are many differences in emphasis as well, that together will require discussion.) Is there currently a list of sources that are agreed upon as having reliable material, and suitable level of presentation? Otherwise, where are we getting our material from?
 * Third and finally, attention would need to be paid to the contributor list, keeping it up to date, and using this Talk as a convenient way to speak to all caring about the text or otherwise involved in the project, so all could be pre-notified about any major change, and collegially discuss any issues that might arise.

title: Talk:Organic Chemistry


text:
A-level Mathematics/OCR/M3/Kinematics

Formulae
You are expected to know the following formulae, as they will not be provided in the formula book:

$$ a = \frac{dv}{dt} = \frac{dv}{dx} \frac{dx}{dt} = v \frac{dv}{dx} $$

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: A-level Mathematics/OCR/M3/Kinematics


text:
Talk:Physics Exercises

Hi! I just reviewed your book for Development stages. I suggest that you have a look how to set mathematical formulae. It would make the excercises easier to read. Have a look at meta:Help:Displaying a formula or check out this example: $$\sin^2(\theta)+\cos^2(\theta)=1$$ --Andreas Ipp 23:57, 12 Jan 2005 (UTC) I was looking for a project like this to contribute. I like to make a database of excercises of physics. I think that a book of Physics exercises would be better if it contains both solved and unsolved problems. What do you think?

--gabrielvc, wikibooks user--

 * I think it is better to have the solutions around somewhere for reference. They don't have to be on the same page though as it is now. Also, the solutions don't have to be written by you, but you might encourage others to provide them. Also, there might be a "Teacher's wikibook" that contains solutions to exercises without solutions in this book? So there is no point in omitting solutions in a wiki... Also, this is the only way to look for errors, should the exercises by accident be wrong or unsolvable... --Andreas 11:37, 10 Apr 2005 (UTC)

Merge into Physics Study Guide?
I think this book would be better served as part of the Physics Study Guide book since the goal is to have worked examples to study from --Martín S-M
 * At the moment, Physics Study Guide links to this book (as an appendix), and IMHO, that seems like the best thing to do. The Study Guide, as a whole, does not focus on problems (more of a quick-review guide, it seemed like), and having problems interpersed throughout the guide will rather be distracting, not to mention it does not serve those students/instructors who are simply looking for problems to work out. I am removing the merge tag, as it appears to have been done already. novakyu (talk) 07:01, 24 December 2007 (UTC)

Automatically numbered equations
How do you do that? Also, is it possible to just upload postscript or PDF files instead of typing text here? Count Iblis 01:02, 27 July 2006 (UTC)
 * Automatically numbered questions are done through HTML lists, or in Wiki markup, by lists starting with "#", like

 * 1) First question
 * 2) Second question
 * I should note that this notation is rather fragile (if you break the list, it'll restart numbering), so there are a lot of stuffs in between, you should use ordered HTML list like (see code)

  First question  Second question
 * And, no, I don't think there's a way to just upload PS or PDF files. There are tools that will turn PS or PDF to HTML code, and you can *probably* more or less paste that in here, but short of making a link to a PS or PDF file (which I don't think is recommended), you can't do that. novakyu (talk) 06:52, 24 December 2007 (UTC)

Refraction exercises
I think A-level Physics (Advancing Physics)/Refraction/Worked Solutions should be included here, either as a copy or as a redirect. Albmont (talk) 20:43, 18 October 2009 (UTC)

title: Talk:Physics Exercises


text:
Japanese/Vocabulary

Elementary vocabulary

 * /Colors/
 * /Clothes and accessories/
 * /Animals/
 * /Numbers/
 * /Time/ and dates
 * Directions
 * Food and drink
 * /Sushi/
 * /Body parts/
 * /Family and people/
 * Weather and seasons
 * /Verbs/
 * /Adjectives/

Proper

 * Countries and languages
 * Regions and prefectures of Japan

Specialized

 * /Academic Subjects/
 * /Astronomy/
 * /Biology/
 * /Chemistry/
 * /Glaciology/
 * /Mathematics/
 * /Linguistics/
 * /Law/
 * /Aviation/
 * /Business/
 * /Banking/
 * /Computing/
 * /Health/
 * Government and politics
 * /Punctuation/
 * /Vocations/
 * /Units/

Cultural

 * /Music/
 * /Videogame/

By origin

 * /Gairaigo/
 * /Onomatopoeia/

জাপানি ভাষা শিক্ষা/অভিধান

title: Japanese/Vocabulary


text:
Portuguese/Contents/Practise Definite and Indefinite Articles

You should have already had a look at the page Definite and Indefinite Articles. If you haven't, have a look over it. Now it's time to have a little practice, as well as learn some vocabulary. It might be best to print this page out or copy it to fill out in a word processing application.

Note that when a word ends in an -s it is plural: to determine whether it is masculine or feminine, take off the -s (or sometimes -es if the word ends in -res, -ses or zes) to determine gender. Pay attention to the real meaning of the word because the way to determine gender needs it. Click here to find the answers.


text:
Student Congress Debate

/Preface/

Introduction to Student Congress

 * A Session Step by Step
 * Speech Structure
 * Cross Examination

Speech in depth

 * Introductions
 * Crafting a Point
 * Refutation, Rebuttal and Rehash
 * Conclusions

Advanced topics

 * Advanced Parliamentary Proceedure
 * Writing Legislation
 * Flowing
 * Research

Contributors
(Please add your name to this list when you contribute to the volume)
 * Linzmeier, Lauren
 * Nordengren, Chase

title: Student Congress Debate


text:
Japanese/Lessons/What is that?

In this lesson you will learn how to ask and identify objects.

What is that?
When you want to ask someone what something is, you might ask
 * Kanji and hiragana: それは何ですか
 * Hiragana: それ　は　なん　です　か
 * Romaji: sore wa nan desu ka?
 * English: What's that?

Words

 * それ means "that" (sore)
 * 何 (なん, nan) means "what" (from なに, nani)
 * Recall that AはBです (A wa B desu) means "A is B."
 * か (ka) is the question particle. Questions are formed by adding か to the end of a sentence. Unlike English, the word order doesn't change. Question words, such as 何 ("what"), simply replace the words you are asking about.

As in English, you would ask about an object depending on its distance from yourself (speaker) and the person you are talking to (listener). In Japanese, there are three words denoting an object's distance from the speaker and listener.
 * これ (kore) "this" - refers to an object near the speaker (e.g., you are holding the object)
 * それ (sore) "that" - refers to an object near the listener (e.g., the person you are talking to is holding the object)
 * あれ (are) "that over there" - refers to an object that is far away from both speaker and listener.

To summarize, これ (kore, this), それ (sore, that), あれ (are, that - far).

That is a...
To reply to the question それは何ですか you would say これは___です. "This is a ___." You should use the name of the object in place of the blank.

In the above question, person A used それ to indicate the object is near person B. In response, person B uses これ to indicate the object is near person B.

Note: The distance of an object from the speaker and listener is taken into consideration when asking or responding to a question. You must familiarize yourself with これ・それ・あれ

Try to remember how to reply to a question with these tips.
 * When someone asks you これ, you reply それ.
 * When someone asks you それ, you reply これ.
 * When someone asks you あれ, you also reply あれ.

も - Also
When you want to ask or say that something is also a type of object, you use the particle も.
 * Question: これ / それ / あれも___ですか "Is this/that/that (far) also a ___?"

There are two possible responses to this question...

If the answer is affirmative, you say 「はい、これ/それ/あれも___です. 」.

If the answer is negative, you say 「いいえ、これ/それ/あれは___では　ありません」. (では is pronounced /dewa/, or /ja/ in less formal conversation.)

 * はい means "yes" or "correct"
 * いいえ means "no" or "incorrect"
 * ___では　ありません means "is not ___". When you want to say something is not a type of object you use this phrase.

の - Possessive particle
The possessive particle, の, is added after a noun or pronoun to indicate that an object belongs to them.

Example
Note: You can omit the name of the object.
 * それは私の___です. "That is my ___."
 * あれは___さんの___ですか. "Is that (far) ___-san's ___?"
 * これは私の___ではありません. "This is not my ___."
 * 私のです. "It's mine."
 * ___さんのです. "It's ___-san's."
 * 私のではありません. "It's not mine."

Whose is this?
A useful phrase to use is 「これは誰の___ですか. 」 (これは　だれの ___　ですか) "Whose ___ is this?" or 「これは誰のですか」 "Whose is this?"

More specific
これ・それ・あれ, which was used to indicate an object's location can be used in their more specific form of この・その・あの to refer to a specific object. Note: これ車, これペン is not possible.
 * この車 (この　くるま) "This (particular) car."
 * そのペン　"That (particular) pen."

Japanese
がくせい：　それはなんですか.

せんせい：　これはりんごです.

がくせい：　これもりんごですか.

せんせい：　いいえ、それはなしです.

English
Student: What is that?

Teacher: This is an apple.

Student: Is this also an apple?

Teacher: No, that is a pear.

Questions
1. How would you ask the following questions?
 * a) What is this?
 * b) What is that (far)?
 * c) What is that?

2. How would you reply to the following questions?
 * a) Q: それは何ですか A: (これ・それ・あれ) は___です.
 * b) Q: あれは何ですか A: (これ・それ・あれ) は___です.
 * c) Q: これは何ですか A: (これ・それ・あれ) は___です.

Answers

 * Answers to Lesson 2

title: Japanese/Lessons/What is that?


text:
Cookbook:Maklubi (Rice with Meat and Vegetables)

| Middle Eastern cuisines | Palestinian Cuisine

Maklubi, also known as maqluba or maklouba, is a dish of rice, meat, and vegetables found throughout the Levant.

Ingredients

 * ½ pound ground beef
 * ½ onion, chopped
 * Olive oil
 * 1 cup rice
 * 1 ½ cups water
 * Salt
 * Black pepper
 * Allspice
 * Plain yogurt

Procedure

 * 1) In a saucepan, brown ground beef and onion with salt, pepper, and allspice in a little olive oil (use more allspice than pepper). Remove from heat.
 * 2) Add the rice and water. Bring to a boil over medium heat.
 * 3) Turn down to medium low, and cover with the lid tilted to let some steam escape.
 * 4) When most of the water has evaporated and the surface of the rice becomes pitted, put the lid on tight. Cook on low heat for 15 minutes.
 * 5) Remove from heat and leave covered for 2–3 minutes. Serve with yogurt.


text:
Cookbook:Tomato Curry

| Curry

This recipe was adapted from Grand Union Cookbook, compiled by Margaret Compton (Grand Union Tea Co., 1902).

Ingredients

 * 1 apple, grated
 * 1 onion, chopped
 * 2 tomatoes, sliced
 * 2 oz (55 g) butter
 * 1 tsp (5 ml) curry powder
 * Milk
 * Salt
 * Black pepper
 * Boiled rice

Procedure

 * 1) Fry apple and onion in the butter until blended.
 * 2) Mix curry powder in a little milk, and stir in.
 * 3) Season with salt and pepper.
 * 4) Fry tomatoes in a separate pan.
 * 5) Cover them with the curry mixture, and serve within a wall of boiled rice.

title: Cookbook:Tomato Curry


text:
Portuguese/Contents/Imperfect tense regular verbs

The Imperfect Tense
The imperfect Tense is used in Portuguese to express something that was happening at a particular moment in time. For instance, we would NOT use the imperfect for the sentence "I ate an apple" because the action has finished. However, the sentence "I was eating an apple" describes something that was happening at a moment in time.

Let's see how to form the imperfect tense. First, take the "ar", "er" or "ir" off the infinitive (so falar becomes fal, comer becomes com and partir becomes part

Regular -er and -ir verbs
You only need to learn one conjugation for the 'ir' and 'er' verbs. That means that the verb partir is conjugated exactly like comer in the imperfect tense.

There! It's that easy.


text:
Portuguese/Imperfect tense irregular verbs

Imperfect Tense Irregular Verbs
If you haven't already had a look at Imperfect tense regular verbs then go there first.

There are four verbs which are conjugated irregularly in Portuguese.

They are vir (to come), ter (to have), ser (to be) and pôr (to put)

VIR - To Come

TER - To Have

SER - To Be

PÔR - To Put


text:
Japanese/Lessons/Existence

When you want to say that something exists, there two verbs you have to choose from depending on whether the subject is an animate- or inanimate object. The difference is not quite living/non-living, as plants would be considered inanimate (as they don't move ... well, most only really slowly). A fish swimming in its fish-bowl would be an animate object, but a dead fish (whether at the fish-mongers or — let's hope not — in its bowl) would be in-animate.

 * For animate objects (humans and animals), use "いる" (polite present positive: "います").
 * For inanimate objects, use "ある" (polite present positive: "あります").

Note that these can denote both presence or possession.

In the dialogues below, you may replace "います" with "あります".

To ask about the presence of a particular animate object
If the animate object in question is not present but something else is, you can suggest this by saying:

Notice that this reply uses "は" instead of "が". The "は" particle can be translated as "as for such and such", while "が" directly marks the subject.

Vocabulary
か: "anything/something". も: "everything/nothing" (positive/negative depends on the verb)

title: Japanese/Lessons/Existence


text:
Robotics/Exotic Robots/BEAM

This page should discus BEAM robots, The Wikipedia link explains what BEAM robots are, other info over this type of robot can be added.

A special kind of robots are BEAM robotics.

title: Robotics/Exotic Robots/BEAM


text:
Abstract Algebra/Matroids

A matroid is an algebraic construct that is related to the notion of independence.

Matroids are an abstraction of several combinatorial objects, among them graphs and matrices. The word matroid was coined by Whitney in 1935 in his landmark paper "On the abstract properties of linear dependence". In defining a matroid Whitney tried to capture the fundamental properties of dependence that are common to graphs and matrices. Almost simultaneously, Birkhoff showed that a matroid can be interpreted as a geometric lattice. Maclane showed that matroids have a geometric representation in terms of points, lines, planes, dimension 3 spaces etc. Often the term combinatorial geometry is used instead of simple matroids. However, combinatorial geometry has another meaning in mathematical literature. Rank 3 combinatorial geometries are frequently called linear spaces. Matroids are a unifying concept in which some problems in graph theory, design theory, coding theory, and combinatorial optimization become simpler to understand.

title: Abstract Algebra/Matroids


text:
Latin/How to study a language on the Internet and in your head

How do you think about languages as you study them? Typically, you will consider every punctuation mark and letter, all the verbs and nouns, adverbs and adjectives, and study them in order to make connections. Ideally, you will have a teacher to point you in the right direction, and help you make those connections. But when you have no teacher, those connections are left for you to discover. They may be clear or hidden, but either way you will have to make them yourself. As you explore this Wikibook, it will require the skill of critical thinking.

You can never go wrong studying a language if you remember that exposing yourself to a language, even if you stumble in practice, is itself learning it. Looking things up too much can sometimes impede progress. Stretch your memory, read slowly, and re-read. As you will soon discover, you are about to study a language that is rich and full of meaning, the ancestor of the Romance languages, such as Spanish, French, Portuguese, Italian, and Romanian, and an outsized influence on many other languages besides, including English.

So do not assume that...
...Latin is like any other language. Do not assume ancient Roman culture is entirely unlike other cultures, however. The Romans grappled with issues that are universally dealt with.

We, the authors, endorse memorization, and after that, immersion. You must develop Latin muscles, and a willingness to write or type things out, or drill using software, or with a friend. Note the patterns after you have memorized the forms, not before. Allow yourself to be mesmerized by them. Similarly, seek out explanation only after you have memorized forms. Memorize forms, then make sentences, then use your knowledge to speak or to write the language.


text:
QBasic/Appendix

ABS
N = ABS(expression returning a numerical value)

Returns the 'absolute' value of the expression, turning a negative to a positive (e.g. -4 to 4)

PRINT ABS(54.345) 'This will print the value ABS now as it is (54.345) PRINT ABS(-43)   'This will print the value as (43).

ACCESS
OPEN "file.txt" FOR APPEND ACCESS WRITE

This sets the access of a file that has been declared into the program. There are three settings that the programmer can set. These are: READ - Sets up the file to be read only, no writing. WRITE - Writes only to the file. Cannot be read. READ WRITE - Sets the file to both of the settings above. FOR APPEND opens the file as a text file and sets the file pointer to the end of the file, thereby appending new output to the file. If omitted, FOR RANDOM is the default, which would open the file as a sequence of fixed-length records and set the file pointer to the start of the file. New data would overwrite existing data in the file without warning.

ASC("C")
PRINT ASC("t") 'Will print 116

Prints the ASCII code number of the character found within the brackets. If the programmer put in a string into brackets, only the first character of the string will be shown.

ATN
ATN(expression)

Part of the inbuilt trigonometry functions. An expression that evaluates to a numeric vale is converted to it's Arc-Tangent. angle = ATN( B ) angle2 = ATN( 23 / 34 )

BEEP
BEEP The BIOS on the motherboard is instructed to emit a "Beep" sound from the PC 'speaker'. See also SOUND and PLAY.

An older, outdated alternative is to use : PRINT CHR$(07)

This was replaced later by the BEEP command.

BLOAD
BLOAD file_path$, memory_offset%

Loads a file saved with BSAVE into memory.
 * file_path$ is the file location
 * memory_offset is an integer specifying the offset in memory to load the file to

The starting memory address is determined by the offset and the most recent call to the DEF SEG statement

BSAVE
BSAVE file_path$, memory_offset%, length&

Saves the contents of an area in memory to a file that can be loaded with BLOAD
 * file_path$ is the file location
 * memory_offset is an integer specifying the offset in memory to save
 * length the number of bytes to copy

The starting memory address is determined by the offset and the most recent call to the DEF SEG statement

CALL ABSOLUTE
CALL ABSOLUTE([argument%, ...,] address%) Pushes the provided arguments, which must be INTEGER, from left to right on the stack and then does a far call to the assembly language routine located at address. The code segment to use is set using DEF SEG. Normally QBasic will push the address of arguments, but if an argument is preceded by BYVAL the value of the argument will be pushed.

Note that because QBasic pushes the arguments from left to right, if you provide three arguments for example the stack will look like this: SS:SP Return IP +0002 Return CS +0004 Argument 3 +0006 Argument 2 +0008 Argument 1 Example: 'POP CX 'POP DX 'POP BX 'POP AX 'MOV [BX], AX 'PUSH DX 'PUSH CX 'RETF A$ = "YZ[Xë•RQ╦" 'Codepage: 437 I% = 42: J% = 0 IF VARSEG(A$) <> VARSEG(J%) THEN STOP 'Both A$ and J% are stored in DGROUP. DEF SEG = VARSEG(A$) CALL ABSOLUTE(BYVAL I%, J%, PEEK(VARPTR(A$) + 3) * 256& OR PEEK(VARPTR(A$) + 2)) PRINT J% QBasic doesn't set BP to the stack frame of your machine language routine, but leaves it pointing to the stack frame of the calling QBasic procedure, which looks like this: -???? Variable 3 -???? Variable 2 -???? Variable 1 -???? Return value (only if the procedure is a FUNCTION, absent if a SUB) -0002 BP of calling procedure SS:BP BP of calling procedure (yes, again) +0002 Six bytes referring back to the calling procedure to use when executing END/EXIT SUB/FUNCTION +0008 Argument 3 +000A Argument 2 +000C Argument 1 The offsets indicated with -/+???? will depend on the sizes and presence of variables, return value and arguments. For example, an INTEGER variable will take two bytes, but a LONG variable four. As one might expect considering how QBasic passes arguments, variables are stored in reverse order of declaration. Contrary to when calling a machine language routine, the arguments here will always be addresses. For arguments passed by value, space is allocated on the stack and the address of that space is passed to the procedure.

CASE
SELECT CASE expression CASE test1[, test2, ...]: statements [CASE test4[, test5, ...]: statements] [CASE ELSE: statements] END SELECT Executes the statements after the first CASE statement where a test matches expression. The tests can be of the following forms: expression expression1 TO expression2 IS {<|<=|=|<>|>=|>} expression This is an example of a program with no CASE commands that assigns different paths to values: PRINT "1. Print 'path'" PRINT "2. Print 'hello'" PRINT "3. Quit" INPUT "Enter a choice: "; a$ IF a$ = "1" THEN PRINT "path": RUN IF a$ = "2" THEN PRINT "hello": RUN IF a$ <> "3" THEN PRINT "That is not a valid choice.": RUN This is what a program looks like with the CASE command: PRINT "1. Print 'path'" PRINT "2. Print 'hello'" PRINT "3. Quit" INPUT "Enter a choice: "; a$ SELECT CASE a$ CASE "1": PRINT "path": RUN CASE "2": PRINT "hello": RUN CASE IS <> "3": PRINT "That is not a valid choice.": RUN END SELECT

CHAIN
CHAIN filename This chains execution to another QBasic program. Values may be passed to the other program by using the COMMON statement before the CHAIN statement. Note that execution doesn't return to the first program unless the second program uses CHAIN to transfer execution back to the first.

CHDIR
CHDIR directoryname This is used for setting the working directory, also known as the current directory. The directory name is declared exactly like in DOS and long file names aren't supported. For example: CHDIR "C:\DOS" Note that this doesn't change the current drive and every drive has its own working directory. You can set the current drive like this: SHELL "C:"

CHR$
This returns the string character symbol of an ASCII code value. name$ = CHR$([ascii character code]) Often used to 'load' characters into string variables when that character cannot be typed (e.g. the Esc key or the F{n} (Function Keys) or characters that would be 'recognised' and acted upon by the QBASIC interpreter. The following four characters cannot occur in a QBasic string literal: Here is a list of some character codes :- 07 Beep (same as BEEP) 08 Backspace 09 Tab 27 Esc 72 Up Arrow 75 Left Arrow 77 Right Arrow 80 Down Arrow
 * 0 Null: all characters up to the end of the line will get deleted, including this one.
 * 10 Line Feed: signals the end of the line.
 * 13 Carriage Return: this character will get deleted.
 * 34 Quotation Mark: signals the end of the string literal.

CINT
This rounds the contents of the brackets to the nearest integer. PRINT CINT(4573.73994596) 4574

CIRCLE
CIRCLE ([X Coordinate], [Y Coordinate]), [Radius], [Colour],[Start],[End],[Aspect] Lets the programmer display a circle. Like all graphics commands, it must be used with the SCREEN command.

CLEAR
CLEAR Resets all variables, strings, arrays and closes all files. The reset command on QBasic.

CLOSE
CLOSE Closes all open files CLOSE #2 Closes only the file opened as data stream 2. Other files remain open

CLS
CLS Clears the active screen. Erases all text, graphics, resets the cursor to the upper left (1,1), and also applies the current background color (this has to be set using the COLOR command) to the whole screen.

COLOR
COLOR [Text Colour], [Background Colour] This lets you change the colour of the text and background used when next 'printing' to the current output window. It can be done like this: COLOR 14, 01 PRINT "Yellow on Blue"

You have a choice of sixteen colours: 00: Black           08: Dark Grey 01: Dark Blue       09: Light Blue 02: Dark Green      10: Light Green 03: Dark Cyan       11: Light Cyan 04: Dark Red        12: Light Red 05: Dark Purple     13: Magenta 06: Orange Brown    14: Yellow 07: Grey            15: White These values are the numbers that you put in the COLOR command.

Note Only screen modes 0, 7, 8, 9, 10 support a background color. To 're-paint' the whole screen in a background colour, use the CLS command.

COMMON
Declares a variable as 'global', which allows its value to be accessed across multiple QBasic programs / scripts (see also the CHAIN command) COMMON SHARED [variablename]

Each program that declares 'variablename' as COMMON will share the same value.

NOTE. All COMMON statements must appear at the start of the program (i.e. before any executable statements).

CONST
Fixes a variable so it can not be changed within the program. CONST (name) {AS (type = INTEGER / STRING)} = (expression or value) For example :- CONST PI = 3.14159265 Assigns the value 3.14159265 to PI. CONST PI2 = 2 * PI PI must be assigned a value before it is used to calculate PI2. Typically all CONST are declared at the beginning of a program.

DATA
DATA [constant] Use in conjunction with the READ and RESTORE command. Mostly used in programs dealing with graphics, this command lets QBasic read a large number of constants. The READ command accesses the data while the RESTORE command "refreshes" the data, allowing it to be used again.

DATE$
A system variable that always contains the current date as a string in mm-dd-yyyy format. Use it like this: a$ = DATE$

DEF SEG
Sets the current segment address. DEG SEG [=address]
 * address is a segment address that can contain a value of 0 through 65535.

If address is omitted, DEF SEG resets the current segment address to the default data segment. DEF SEG is used by BLOAD, BSAVE, CALL ABSOLUTE, PEEK, and POKE

DEST(Only QB64!)
_DEST sets the current write-to page or image. _DEST image_handle sends the destination image to an image of handle stored in long variable image_handle. _DESt 0 sends the destination image to the current screen being used.

DIM
This is used to declare an array (early versions of QBasic required all variables to be defined, not just arrays greater than 10)

DIM [Array Name] ([count],[count], ..)

The Array name can be of any type (Integer, Double, String etc). If not declared, single precision floating point is assumed. Strings can be 'declared' using $ sign (Integers with the '%' sign). The QBASIC interpreter tolerates numeric arrays of up to 10 count without these needing to be declared.

NOTE Early versions of QBasic did not explicitly set the contents of an array to zero (see CLEAR command)

DIM table%(100,2) Create an integer array called table% containing 100x2 = 200 entries

DIM form$(5) Create a string array called form$ containing 5 strings

DIM quotient(20) AS DOUBLE Create an array called quotient that contains 20 double precision numbers

DO .. LOOP
DO [program] LOOP UNTIL [test condition becomes TRUE] Used to create a loop in the program. The [condition] is tested only after the [program] code is executed for the first time (see also WHILE). For example: num$ = 1 sum$ = 0 DO sum$ = 2 * num$ PRINT sum$ num$ = num$ + 1 LOOP UNTIL num$ = 13

This does not work But the following does

num = 1 sum = 0 DO sum = 2 * num PRINT sum num = num + 1 LOOP UNTIL num = 13

DRAW
DRAW "[string expression]" Used to draw a straight line from the current 'cursor' position in the current colour. DRAW defines the direction (up, down etc.) and the length of the line (in pixels). For example:- SCREEN 7 PSET (50, 50), 4 DRAW "u50 r50 d50 l50" The letter in front of each number is the direction: U = Up   E = Upper-right D = Down F = Lower-right L = Left G = Lower-left R = Right H = Upper-left

The drawing 'cursor' is left at the position where the line ends. u50 draws from 50,50 upwards ending at 50,0 r50 draws from 50,0 to the right, ending at 100,0 d50 draws from 100,0 downwards, ending at 100,50 l50 draws from 100,50 to the left, ending at 50,50

The example shown will thus draw a red 'wire frame' square.

See also LINE and CIRCLE commands.

Note: The diagonal from 0,0 to 100,100 will be 100 * root(2) pixels long (i.e. 141)

END
END Signifies the end of the program. When QBasic sees this command it usually comes up with a statement saying: "Press Any Key to Continue".

END TYPE / END DEF / END SUB / END FUNCTION / END IF / END SELECT

 * ends a TYPE definition.
 * ends a DEF FN function definition.
 * ends a SUB procedure definition.
 * ends a FUNCTION procedure definition.
 * ends a multiline IF block.
 * ends a SELECT CASE block.

ENVIRON
ENVIRON [string expression] NOTE: If you are running QBasic on a Windows system, you will not be able to use this command.

This command helps you set an environment variable for the duration of the session. On exit from the QBasic.exe interpreter, the variables revert to their original values.

EOF
This checks if there are still more data values to be read from the file specified in. EOF returns a boolean / binary value, a one or zero. 0 if the end of file has not been reached, 1 if the last value in the file has been read (see also LINE INPUT)

OPEN File.txt FOR INPUT AS #1 DO INPUT #1, text$ PRINT text$ LOOP UNTIL EOF(1) END

Note that, since the INPUT is executed before UNTIL is reached, File.txt must contain at least one line of text - if the file is empty, you will receive an 'ERROR (62) Input past end of file'.

ERASE
ERASE [arrayname] [,] Used to erase all dimensioned arrays.

ERROR
System variable holding a numeric value relating to the processing of the previous line of code. If the line completed without error, ERROR is set to 0. If the line failed, ERROR is set to one of the values shown below. Most commonly used to redirect program flow to error handling code as in :- ON ERROR GOTO [line number / label] If ERROR is non=zero, program flow jumps to the line number or label specified. If ERROR is zero, program flow continues with the next line below.

To manually test your program and check to see if the error handling routine runs OK, ERROR can be set manually :- ERROR [number] Set ERROR = number

The error numbers are as follows: 1 NEXT without FOR                39 CASE ELSE expected 2 Syntax Error                    40 Variable required 3 RETURN without GOSUB            50 FIELD overflow 4 Out of DATA                     51 Internal error 5 Illegal function call           52 Bad file name or number 6 Overflow                        53 File not found 7 Out of memory                   54 Bad file mode 8 Label not defined               55 File already open 9 Subscript out of range          56 FIELD statement active 10 Duplicate definition           57 Device I/O error 11 Division by zero               58 File already exists 12 Illegal in direct mode         59 Bad record length 13 Type mismatch                  61 Disk full 14 Out of string space            62 Input past end of file 16 String formula too complex     63 Bad record number 17 Cannot continue                64 Bad file name 18 Function not defined           67 Too many files 19 Yes RESUME                      68 Device unavailable 20 RESUME without error           69 Communication-buffer overflow 24 Device timeout                 70 Permission denied 25 Device Fault                   71 Disk not ready 26 FOR without NEXT               72 Disk-media error 27 Out of paper                   73 Advanced feature unavailable 29 WHILE without WEND             74 Rename across disks 30 WEND without WHILE             75 Path/File access error 33 Duplicate label                76 Path not found 35 Subprogram not defined 37 Argument-count mismatch 38 Array not defined

Note that ERROR is set when execution fails, not when the code is 'read' - so, for example, a 'divide by 0' will be found before the result is assigned to a non-existent array variable or written to a non-existent file.

EXIT
Allows the immediate exit from a subroutine or a loop, without processing the rest of that subroutine or loop code

EXIT DEF Exits from a DEF FN function. EXIT DO Exits from a DO loop, execution continues with the command directly after the LOOP command EXIT FOR Exits from a FOR loop, execution continues with the command directly after the NEXT command EXIT FUNCTION Exits a FUNCTION procedure, execution continues with the command directly after the function call EXIT SUB Exits a SUB procedure.

FOR .. NEXT
FOR [variable name] = [start value] TO [end value] {STEP n} [program code] NEXT [variable name]

The variable is set to the [start value], then program code is executed and at the Next statement the variable is incremented by 1 (or by the STEP value, if any is specified). The resulting value is compared to the [end value] and if not equal program flow returns to the line following the FOR statement.

For example: FOR a = 200 TO 197 STEP-1 PRINT a NEXT a

200 199 198

Care must be taken when using STEP, since it is quite possible to step past the (end value) with the result that the FOR loop will run 'for ever' (i.e. until the user aborts the interpreter or an error occurs), for example :-

FOR a = 200 TO 197 STEP-2 PRINT a NEXT a

200 198 196 194 192 ... 0 -2 -4 ... -32768 ERROR overflow

GOSUB
GOSUB [subroutine line number / label] Command processing jumps to the subroutine specified. When the RETURN command is encountered, processing returns to this point and continues with the line below the GOSUB.

IF
IF [variable or string] [operator] [variable or string] THEN [command] {ELSE [command]} Compares variables or strings. For example, if you wanted to examine whether or not a user-entered password was the correct password, you might enter: IF a$ = "password" THEN PRINT "Password Correct" Where a$ is the user entered password. Some operators include: "="- equal to "<"- less than (only used when variable or string is a number value) ">"- greater than (only used when variable or string is a number value) "<>"- does not equal "<="- less than or equal to (only used when variable or string is a number value) ">="- greater than or equal to (only used when variable or string is a number value) One can also preform actions to number values then compare them to other strings or variables using the if command, such as in the below examples: IF a+5 = 15 THEN PRINT "Correct" IF a*6 = b*8 THEN PRINT "Correct"

INCLUDE (QUICKbasic Only)
QUICKBasic supports the use of include files via the $INCLUDE directive: (Note that the Qbasic interpreter does NOT support this command.)

'$INCLUDE: 'foobar.bi'

Note that the include directive is prefixed with an apostrophe, dollar, and that the name of the file for inclusion is enclosed in single quotation mark symbols.

INKEY$
[variable] = INKEY$ This is used when you want a program to function with key input from the keyboard. Look at this example on how this works: a$ = INKEY$ PRINT "Press Esc to Exit" END IF a$ = CHR$(27) You can use this in conjunction with the CHR$ command or type the letter (e.g. A).

INPUT
INPUT [String Literal] [,or;] [Variable] Displays the String Literal, if a semi colon follows the string literal, a question mark is displayed, and the users input until they hit return is entered into the variable. The variable can be a string or numeric. If a user attempts to enter a string for a numeric variable, the program will ask for the input again. The String Literal is option. If the string literal is used, a comma or semicolon  is necessary.

INPUT #
INPUT #n [String Literal] [,or;] [Variable] Reads a string / value from the specified file stream (see also LINE INPUT #) INPUT #1, a$, b$, n, m Reads 4 values from the file that is OPEN as #1. a$ is assigned all text until a ',' (comma) or end of line is reached, b$ the next segment of text, then two numeric values are interpreted and assigned to n and m.

Note that, within the file, numbers can be separated by 'anything' - so, if a number is not found (for 'n' or 'm') on the current 'line' of the file, the rest of the file will be searched until a number is found. Input is then left 'pointing' at the position in the file after the last number required to satisfy the input statement (see also 'seek #' command)

INSTR
INSTR (start%, Search$, Find$) Returns the character position of the start of the first occurrence of Find$ within Search$, starting at character position 'start%' in Search$. If Find$ is not found, 0 is returned. start% is optional (default = 1, the first character of Search$) Pos = INSTR ("abcdefghi", "de") returns 4

LEFT$
A$ = LEFT$(B$,N)

A$ is set to the N left most characters of B$.

A$ = LEFT$("Get the start only",6)

returns "Get th"

See also RIGHT$, MID$.

LET
LET [variable] = [value] Early versions of the QBasic.exe command interpreter required use of the 'LET' command to assign values to variables. Later versions did not.

LET N = 227 / 99 LET A$="a line of simple text"

is equliavent to :-

N = 227 / 99 A$="a line of simple text"

LINE
LINE ([X], [Y]) - ([X], [Y]), [Colour Number] Used for drawing lines in QBasic. The first X and Y are used as coordinates for the beginning of the line and the second set are used for coordinating where the end of the line is. You must put a SCREEN command at the beginning of the program to make it work.

Note. When in SCREEN 13, the Colour Number == the Palette number

LINE INPUT #
LINE INPUT #1, a$ Reads a complete line as text characters from the file OPEN as stream #1 and places it in a$.

To find the 'end of line', the QBasic interpreter seaches for the 'Carriage Return' + 'Line Feed' (0x0D, 0x0A) characters. When reading text files created on UNIX/LINUX systems (where the 'Line feed' 0x0A is used on it's own to signify 'end of line'), LINE INPUT will not recognise the 'end of line' and will continue to input until the end of file is reached. For files exceeding 2k characters, the result is an "Out of String Space" Error as a$ 'overflows'. One solution is to use a text editor able to handle UNIX files to open and 'save as' before attempting to process the file using QBasic.

LOADIMAGE (QB64 Only)
(NOTE! The commands in this section refer to a third-party program called "QB64". Neither QUICKbasic nor Qbasic support _LOADIMAGE, _NEWIMAGE, OR  _PUTIMAGE commands. Both QUICKbasic and Qbasic have a "SCREEN" command, but it works diffently in those languages than in QB64.)

_LOADIMAGE("image.jpg")

Shows an image. Must be used with the commands SCREEN, _NEWIMAGE and _PUTIMAGE.

Example:

DIM rabbit AS LONG SCREEN _NEWIMAGE(800, 600, 32) rabbit = _LOADIMAGE("rabbit.jpg") _PUTIMAGE (100,100), rabbit

LOOP
DO [Program] LOOP UNTIL [condition] Used to create a loop in the program. This command checks the condition after the loop has started. This is used in conjunction with the DO command.

LPRINT
LPRINT [statement or variable] Prints out text to a printer. The LPRINT command expects a printer to be connected to the LPT1(PRN) port. If a printer is not connected to LPT1, QBasic displays a "Device fault" error message.

If your printer is connected to a COM port instead, use the MS-DOS MODE command to redirect printing from LPT1 to COMx (for example, to redirect to COM1, use the following command:   MODE LPT1=COM1

If you need to cancel the redirection when finished, use the following command: MODE LPT1

MID$
a$=MID$(string$,start%[,length%]) MID$(string$,start%[,length%])=b$

In the first use, a$ is set to the substring taken from string$ strating with character start% taking Length% characters. If length% is omitted, the rest of the line (i.e. start% and all the characters to the right) are taken.

In the second use, length% characters of string$ are replaced by b$ starting at start%. If length% is omitted, the rest of the line is replaced (i.e. start% and all the characters to the right)

See also LEFT$ RIGHT$ LEN

MOD
a MOD b

Returns the remainder of an integer divide of a by b

For example, 10 MOD 3 returns 1

NEWIMAGE(Only QB64!)
_NEWIMAGE is used to set a long variable as the screen dimensions, or can be used with the SCREEN command (See later in Appendix) to directly set the screen details. It is very useful as you can enlarge the SCREEN mode '13' which has RGB color settings if you find the default size too small.

Syntax: _NEWIMAGE(width,length,screen_mode) Like, _NEWIMAGE(1000,1000,24),256 where, 256 is the amount of colours
 * width and length are long variables, while screen_mode is the screen mode format you wish to change.

It is also used to prepare the window screen surface for the image you want to put (first load it using LOADIMAGE).

OPEN
OPEN "[(path)\8.3 file name.ext]" (FOR {INPUT/OUTPUT} AS #{n}) This opens a file. You have to give the DOS file name, for example: OPEN "data.txt" FOR INPUT AS #1 Opens the existing file data.txt for reading as data stream #1. Since no path is specified, the file must be in the same folder as the QBasic.exe - if not, processing halts with a 'file not found' error OPEN "C:\TEMP\RUN.LOG" FOR OUTPUT AS #2 Opens an empty file named RUN.LOG in the C:\TEMP folder for writing data stream #2. Any existing file of the same name is replaced.

PALETTE
PALETTE[palette number, required colour] For VGA (SCREEN mode 13) only, sets the Palette entry to a new RGB color. The palette number must be in the range 1-256. The required colour is a LONG integer created from the sum of (required Blue * 65536) + (required Green * 256) + required Red.

RANDOMIZE
RANDOMIZE TIMER A = INT((RND * 100)) + 1

RANDOMIZE will set the seed for QBasic's random number generator. With QBasic, it's standard to simply use RANDOMIZE TIMER to ensure that the sequence remains the same for each run.

The example is a mathematical operation to get a random number from 1 to 100.

INT stands for Integer, RND for Random and "*" stands for the limit upto which the random number is to be chosen. The "+ 1" is just there to ensure that the number chose is from 1 to 100 and not 0 to 99.

Note: Subsequent calls of this function do not guarantee the same sequence of random numbers.

READ
READ AIM(I) Used in conjunction with the DATA command, this command lets QBasic read data. This is mostly used when dealing with large quantities of data like bitmaps.

REM or '
REM {comments} ' {comments} When the interpreter encounters REM or " ' " (a single quote) at the start of a line, the rest of the line is ignored

RETURN
RETURN Signifies that it is the end of a subroutines

RND
RANDOMIZE TIMER A = INT((RND * 100)) + 1

RND will provide a random number between 0 and 1.

The example is a mathematical operation to get a random number from 1 to 100. RANDOMIZE TIMER will set the initial seed to a unique sequence. INT stands for Integer, RND for Random and "*" stands for the limit upto which the random number is to be chosen. The "+ 1" is just there to ensure that the number chose is from 1 to 100 and not 0 to 99.

Internally, the seed a 24-bit number, iterated in the following method: rnd_seed = (rnd_seed*16598013+12820163) MOD 2^24

PLAY
PLAY "[string expression]" Used to play notes and a score in QBasic on the PC speaker. The tones are indicated by letters A through G. Accidentals are indicated with a "+" or "#" (for sharp) or "-" (for flat) immediately after the note letter. See this example: PLAY "C C# C C#" Whitespaces are ignored inside the string expression. There are also codes that set the duration, octave and tempo. They are all case-insensitive. PLAY executes the commands or notes the order in which they appear in the string. Any indicators that change the properties are effective for the notes following that indicator. Ln    Sets the duration (length) of the notes. The variable n does not indicate an actual duration amount but rather a note type; L1 - whole note, L2 - half note, L4 - quarter note, etc. (L8, L16, L32, L64, ...). By default, n = 4. For triplets and quintets, use L3, L6, L12, ... and L5, L10, L20, ... series respectively. The shorthand notation of length is also provided for a note. For example, "L4 CDE L8 FG L4 AB" can be shortened to "L4 CDE F8G8 AB". F and G play as eighth notes while others play as quarter notes. On    Sets the current octave. Valid values for n are 0 through 6. An octave begins with C and ends with B.       Remember that C- is equivalent to B.  < >    Changes the current octave respectively down or up one level. Nn    Plays a specified note in the seven-octave range. Valid values are from 0 to 84. (0 is a pause.) Cannot use with sharp and flat. Cannot use with the shorthand notation neither. MN    Stand for Music Normal. Note duration is 7/8ths of the length indicated by Ln. It is the default mode. ML    Stand for Music Legato. Note duration is full length of that indicated by Ln. MS    Stand for Music Staccato. Note duration is 3/4ths of the length indicated by Ln. Pn    Causes a silence (pause) for the length of note indicated (same as Ln). Tn    Sets the number of "L4"s per minute (tempo). Valid values are from 32 to 255. The default value is T120. .     When placed after a note, it causes the duration of the note to be 3/2 of the set duration. This is how to get "dotted" notes. "L4 C#." would play C sharp as a dotted quarter note. It can be used for a pause as well. MB MF Stand for Music Background and Music Foreground. MB places a maximum of 32 notes in the music buffer and plays them while executing other statements. Works very well for games. MF switches the PLAY mode back to normal. Default is MF.

PRINT
PRINT [Argument] [,or;] [Argument]... Displays text to the screen. The Argument can be a string literal, a string variable, a numeric literal or a numeric variable. All arguments are optional. PRINT #[n] [,or;] [Argument]... Saves data to the file that is 'OPEN FOR OUTPUT AS #[n]' or we can use ? symbol for print command

PSET
PSET ([X coordinate],[Y coordinate]), [Pixel Colour] This command displays pixels, either one at a time or a group of them at once. For the command to work, the program must have a SCREEN command in it.

SCREEN
SCREEN [Screen Mode Number] This command is used for displaying graphics on the screen. There are ten main types of screen modes that can be used in QBasic depending on the resolution that you want. Here is a list of what screen modes you can choose from:

SCREEN 0: Textmode, cannot be used for graphics. This the screen mode that text based programs run on.

SCREEN 1: 320 x 200 Resolution. Four Colours

SCREEN 2: 640 x 200 Resolution. Two Colours (Black and White)

SCREEN 7: 320 x 200 Resolution. Sixteen Colours

SCREEN 8: 640 x 200 Resolution. Sixteen Colours

SCREEN 9: 640 x 350 Resolution. Sixteen Colours

SCREEN 10: 640 x 350 Resolution. Two Colours (Black and White)

SCREEN 11: 640 x 480 Resolution. Two Colours

SCREEN 12: 640 x 480 Resolution. Sixteen Colours

SCREEN 13: 320 x 200 Resolution. 256 Colours. (Recommended)

Note. In SCREEN 13 you have a colour Palette of 256 colours. The PALETTE is pre-set by Windows however you can change the RGB values using the PALETTE command.

SEEK
SEEK #[file number], 1 Repositions the 'input #' pointer to the beginning of the file.

SGN
SGN(expression yielding a numeric value)

Yields the 'sign' of a value, -1 if < 0, 0 if 0, 1 if > 0

SHELL
The 'SHELL' command is used in Qbasic to issue a command to Command Prompt/Windows Shell. The 'Shell' command is used along with a string that contains commands that would be understood by any of the above software. The string enclosed commands are much like that of MS-DOS

Example: SHELL can be used with a 'DIR' command to make a directory of files in a certain folder or path.

SLEEP
SLEEP [n] Execution is suspended for n seconds

SOUND
SOUND [frequency], [duration] Unlike the BEEP command, this produces a sound from the PC speakers that is of a variable frequency and duration. The frequency is measured in Hertz and has a range from 37 to 32767. Put in one of these numbers in the frequency section. The duration is clock ticks that is defaulted at 18.2 ticks per second.

STR$
Converts a numeric value into a text (string) character

A$ = STR$(expression yielding a numeric value)

The numeric value is converted into text characters and placed into A$. Use to convert numbers into a text string.

WARNINGS.

1) If the result is positive, a leading 'space' is added (STR$(123) = " 123" and not "123" as might be expected). If the result is negative, instead of a space you get a '-' (minus sign), i.e. STR$(-123) = "-123" and not " -123" as might be expected from the positive behaviour.

2) When converting a float (mumb!, numb#) less than 0.1, the string value may be rendered in 'scientific notation', with 'D' used rather than '*10^' (for example "5.nnnnnnD-02" rather than " .05nnnnnn" or "5.nnnnnn*10^-02"). This only occurs when the number of significant digits needs to be preserved (so .03000000 is rendered as " .03", whilst .030000001 becomes " 3.0000001D-02"), again perhaps not what you might expect.

See also CHR$ for converting an ascii value into a string character.

See also LEFT$, MID$, RIGHT$ for extracting sub-strings from a line of text.

SYSTEM
SYSTEM The .bas exits, the QBasic.exe interpreter is closed and 'control' passes to the Command Window c:\ prompt (or next line of a calling .cmd script etc.)

NOTE!: This only works when you start your program at the command prompt using the "/run" parameter! (EX: "Qbasic /run MyProg.bas") Otherwise, Qbasic assumes you opened your program to make changes, and thus "SYSTEM" drops you back at the editor screen.

THEN
[Command] [variable] = [value] THEN GOTO [line command value] Used in conjunction with the GOTO or IF condition commands. It tells the computer what to do if a certain condition has been met.

TO
[Command] [Variable] = [Value] TO [Value] Usually used to input a number of variables. FOR a = 400 TO 500 PRINT a NEXT a This example will print all numbers from 400 to 500. Instead of declaring all values separately, we can get them all declared in one go.

USING
USING "format"; Used to format the output of data from PRINT commands. Normally, the QBasic interpreter will print a number as 8 characters with as many leading spaces as necessary. To change this behavour, the USING command can be used to format the output. For example ..

IF n > 99 THEN PRINT #1, USING "###"; n; ELSE IF n > 9 AND n<=99 THEN PRINT #1, USING "0##"; n; ELSE PRINT #1, USING "00#"; n;

.. will output n from 0 to 999 with leading zeros. Note the ';' after the n. This means 'don't start a new line' and results in the next PRINT #1 adding data directly after the comma (',') Qbasic automatically inserts instead of a line.

VAL
name=VAL([variable$]) Converts the [variable string] contents into a numeric value so it can be used in calculations. If (name) is an INTEGER type, the VAL is rounded down. See also STR$.

A$ = "2"

B$ = "3"

X = VAL(A$) + VAL(B$)

PRINT A$; " + "; B$; " ="; X

WHILE ... WEND
WHILE {NOT} [test condition is true] [program code to execute] WEND The condition is tested and if true (or NOT true) the [program] code is executed until WEND is reached, at which point control passes back to the WHILE line. WHILE NOT (EOF(1)) LINE INPUT #1, A$ PRINT #2, A$ WEND While the end of file #1 has not been reached, read each complete line and write it to file #2.

Unlike FOR and DO, it is not possible to EXIT from a WHILE loop

title: QBasic/Appendix


text:
IB Spanish

Group 2 Spanish
Spanish B Higher Level (HL) suits someone who has studied the language for 4-5 years. Spanish Standard Level (SL) is suited to someone who has 2-5 years experience. Beginners should opt for Spanish ab initio. Native or bilingual speakers, if already doing English or French in Group 1, should take Spanish A2 in Group 2. This wikibook focuses on Spanish B HL and SL.

Differences between HL and SL
The structure of the course should be similar whether studying HL or SL. However, HL students should have more allocated teaching time and more homework. In addition, HL students should be exposed to more complex language, be introduced to a variety of literary styles and explore more culture. While a SL student would be expected to communicate orally and in writing in a variety of common situations and with a certain degree of fluency, a HL student would be expected to communicate orally and in writing in a wide variety of situations with clarity and fluency. SL and HL are differentiated by the recommended number of teaching hours, the depth of syllabus coverage, the study of literature at HL, and the level of difficulty and demands of assessment and assessment criteria. The core—with topics common to both levels—is divided into three areas and is a required area of study. • Communication and media • Global issues • Social relationships In addition, at both SL and HL, teachers select two from the following five options. • Cultural diversity • Customs and traditions • Health • Leisure • Science and technology

Also, at HL, students read two works of literature.

Syllabus
There is one Language B Guide that covers all (30+) languages taught in Group 2. This means that it is the responsibility of the teacher to design a course suitable for the needs of the students. Despite this freedom, there are two main strands around which a teacher can base his own course: Text Type (or Communicative Purpose) and Topics. In addition, the four skills of listening, speaking, reading and writing should be interlinked throughout the course.

Types of Text
The IB Spanish course is intended to prepare students to be able to understand and write a variety of types of texts, including: brochures, diary entries, police statements, anecdotes or short stories,  informal letters and emails, formal letters and emails, letters to a newspaper, news articles, opinion articles (editorials/columns), essays, reports, book reviews and film reviews. Students should also learn to write “spoken” texts such as interviews, speeches and conference presentations. The more complex texts should be reserved for HL students, for example: interviews, conference presentations, essays and creative writing.

Topics
Anything related to Hispanic culture, society and history can be studied, as well as issues relating to young people and the international community, for example:

El deporte, la salud, el ocio, la moda, el botellón, el papel de la mujer, el machismo, las relaciones personales, el amor, el turismo, el medio ambiente, la solidaridad, la globalización, la educación, la lectura, la tecnología, el internet, el espanglish, las comunidades indígenas, las fiestas, las tradiciones, la tauromáquia, el flamenco, los gauchos, el tango argentino, la gastronomía, el arte, el cine, el narcotráfico, la política, los conflictos internacionales, la inmigración.

Authentic Resources
It is very easy to find authentic resources in Spanish on the internet. For the news and current affairs use high quality websites such as http://www.rtve.es (Radio y televisión española), http://www.elpais.es, http://www.elmundo.es. Don’t limit yourself to articles; search in the archives for videos and podcasts too. http://www.youtube.com is fantastic for music videos (with lyrics), interviews with famous people, publicity, and is a lively source of background information on almost any topic. Films are a must for any student wanting to explore issues of culture and society. Films made in Spain and Latin America are becoming increasingly mainstream in the UK and are equally accessible to SL and HL students, for example: Volver, María llena eres de gracia, Amores Perros, Y tu mamá también, El orfanato, El laberinto del fauno, La lengua de las mariposas.

Literature
HL Students are required to read two "works" authentic literature, such as whole books or plays or collections of poems or short stories. Accessible authors to start with include Federico García Lorca (La casa de Bernarda Alba, Bodas de Sangre), Laura Esquivel (Como agua para chocolate), Carlos Fuentes (Aura). Extracts of lengthier works can be studied in order to gain an appreciation for different styles including Gabriel García Márquez (Cien años de soledad, Crónica de una muerte anunciada), Miguel Delibes (Cinco Horas con Mario), Fernando Fernán Gómez (Las bicicletas son para el verano), Jorge Luis Borges (Ficciones), Miguel de Cervantes (Novelas ejemplares), Juan Rulfo (Pedro Párramo), Pablo Neruda (Confieso que he vivido), Mario Vargas Llosa (La fiesta del chivo) Roberto Bolaño (Los detectives salvajes), Mario Benedetti (Aquí se respira bien), Luisa Castro (La segunda mujer).

Assessment and grading
Students sit two written exams: Paper 1 and Paper 2, each lasting 1hr30. In addition, a written assignment is produced under teacher supervision during the school year. Internal Assessment comprises Interactive Orals and an Individual Oral. Students are assessed throughout on their Language, Interaction and Message.

The grade boundaries shift slightly in every exam sessions, and remain to be established in the new program for initial testing in 2013.

Externally assessed written assignment: This paper, new to the curriculum for 2013, is written by students under teacher supervision, but submitted for external evaluation. For HL, the paper is based on the literature topics studied. For SL, it is based on a selection of three related non-literary readings which the student uses as a basis for the paper.

Paper 1 (Text Handling) 1hr30    25%
Section A) Reading Comprehension: 30-40 questions based on 4 texts (Texts A, B and C). Question types include true or false with a justification, looking for synonyms, inserting conjunctions, identifying which noun a pronoun refers to, matching titles with paragraphs, multiple choice, identifying the main purpose of the text. All answers should be exact words lifted from the text; do not try to explain or paraphrase. 1 mark is allocated to each question.

Paper 2 (Writing in Registers) 1hr30    25%
Students have a choice of 5 topics covering different areas of study and types of text. In addition, HL students have a second written item reacting to a short reading.

Internal Assessment  30%
Interactive Oral: At least 3 group orals should be assessed in the final year of the course and the best mark is put forward. Interactive Orals can take many forms, for example: a prepared presentation followed by questions, a formal debate, an informal discussion, a role-play, or a spontaneous response to a film-clip. Interactive orals are marked by the teacher. The more orals done in class, the less nerve-wrecking they become.

Individual Oral: The Individual Oral takes place in the final year and lasts 8-10 minutes. It is conducted and marked by the teacher and recorded for external moderation. The mark is added to the best Interactive Oral mark. Part 1 is a 3-4 minute presentation on a picture related to a curriculum theme. Part 2 involves 5-6 minutes of unprepared discussion with the teacher based on the picture's topic.

Extended Essay in Spanish
Students can choose to write their Extended Essay (la monografía) in Spanish as part of Group 2. The EE can be written either on aspects of Language, Culture & Society, or Literature. Students should read carefully the Extended Essay Guide (2009) and the Group 2 Subject Specific criteria. Writing the EE in Spanish is excellent preparation for university study of the language.

title: IB Spanish


text:
A-level Mathematics/OCR/M3/SHM

Defining Equation of Motion (in terms of acceleration and displacement)
By definition, a particle performs simple harmonic motion (SHM) when
 * the magnitude of its acceleration $$\ddot{x}$$ is proportional to the magnitude of its displacement $$x$$ from some fixed point, and
 * its acceleration and displacement are in opposite directions.

More formally, SHM occurs whenever the equation of motion $$\ddot{x}=-kx$$ holds, where $$k$$ is a positive constant. By convention, we write $$k=\omega^2$$ (we will explain the significance of $$\omega$$ later) so the equation becomes $$\ddot{x}=-\omega^2 x$$.

Simple harmonic oscillators are easy to find in the real world. The undamped oscillation of a mass attached to an elastic string or spring is just one example in the realm of mechanics. Before studying such examples, let us first examine the characteristics of SHM using the abstract model described below.

Consider the following oscillator with an oscillation amplitude of $$a$$. Let $$x$$ denote its displacement from the origin, and $$\ddot{x}$$ its acceleration.

Let us restate the defining equation for SHM:

Recall that the algebraic variables representing displacement and its derivatives wrt time represent one-dimensional vector quantities (i.e. they all lie on a line). If the value of the variable is positive, then its vector points in the positive direction; if it is negative, its vector points in the other direction.

Observe that when the $$x=0$$, then $$\ddot{x}=0$$. By Newton's Second Law, the resultant force $$F$$ acting on the oscillator is zero at this instance.

When $$x>0$$ (i.e. to the right of the origin), the resultant force points to the left, towards the origin. When $$x<0$$, the resultant force points to the right, towards the origin. Because the resultant force always points towards the origin whenever the oscillator is not at the origin, the resultant force can be termed a restoring force. The behaviour of the restoring force suggests that the speed of the oscillator is maximum at the origin and is zero at the two ends where it changes direction (i.e. $$v=0$$ when $$x=\pm a$$).

Equation of Motion, in terms of velocity, amplitude and displacement
Now, let us rewrite the defining SHM equation in terms of the velocity $$v$$ and displacement $$x$$. We make the following substitution: $$\ddot{x}=\frac{dv}{dt}=\frac{dv}{dx}\frac{dx}{dt}=v\frac{dv}{dx}$$. It follows that

Using $$v=0$$ and $$x=\pm a$$ as one pair of limits for the integral, we get

Now, it is clear that the speed is maximum when $$x=0$$ (in which case $$v=\pm\omega a$$), and $$v=0$$ when $$x=\pm a$$.

Equation of Motion, in terms of displacement, amplitude and time
The significance of the constant $$\omega$$ will become clear once we express the defining SHM equation in terms of the displacement $$x$$ and time $$t$$:

This is just a ''second-order ordinary differential equation with constant coefficients''. The characteristic equation (as a function of $$m$$) is given by:

$$ m^2 + \omega^2 =0 \Rightarrow m = \pm \sqrt{-\omega^2} \Rightarrow m = \pm \mathrm{i}\omega $$

Thus, the general solution to the differential equation may be written as:

$$x=A_1\cos (\omega t) + A_2\sin (\omega t)\,$$, or equivalently, $$x=A_3\cos (\omega t + \varepsilon)\,$$.

To solve for the pairs of constants $$\{A_1,A_2\}$$ or $$\{A_3,\varepsilon\}$$, we need a pair of initial conditions describing the SHM.

If the particle starts from rest at the maximum displacement $$x=a$$, then we substitute $$x=a$$ and $$\frac{dx}{dt}=0$$ at $$t=0$$ to get $$A_1=a$$, $$A_2=0$$ and $$A_3=a$$, $$\varepsilon=0$$. The solution becomes $$x=a \cos (\omega t)\,$$.

On the other hand, if the oscillation begins at minimium displacement, then we obtain $$x=a \sin (\omega t)=a\cos\left(\omega t - \frac{\pi}{2}\right)\,$$.

In general, we have

where the constant $$\varepsilon$$ depends on the starting position of the oscillator.

These equations show that $$\omega$$ is just the constant angular velocity (or angular frequency) associated with the SHM. The following figure illustrates this relationship between SHM and uniform circular motion (with an angular velocity of $$\omega$$). The displacement $$x$$ of the simple harmonic oscillator is really just the $$x$$-coordinate of the particle performing uniform circular motion. We can therefore think of SHM as a projection of uniform circular motion onto the diameter of the circle.

The simple harmonic oscillator completes one oscillation whenever it traverses twice the end-to-end distance (i.e. a distance of $$4a$$). This corresponds to one revolution around the circle in the case of uniform circular motion. Thus, the period of oscillation in SHM is given by

Example: Mass on an Elastic String
We wish to determine if a mass suspended on a light (i.e. massless) elastic string will demonstrate SHM.

Consider a light elastic string with natural length $$l$$ and modulus of elasticity $$\lambda$$ suspended vertically from a fixed point O. The other end of the string is attached to a particle of mass $$m$$.

Let the point E denote the equilibrium position of the particle. At E, the particle is at rest (i.e. the resultant force acting on it is zero). Let $$e$$ denote the extension of the string when the particle is at E. Considering the vertical forces on the particle gives:

$$\frac{\lambda}{l}e = mg \Rightarrow e= \frac{mgl}{\lambda}$$.

The displacement $$x$$ of the mass is always measured from the equilibrium position E, since this is the point where $$\ddot{x}=0$$ and hence, the resultant force $$F=0$$.

Suppose the mass experiences a small displacement $$x$$. Applying Newton's Second Law produces

which is the defining equation of motion for SHM, with $$\omega^2 = \frac{\lambda}{ml}$$. Note that the particle performs SHM only when the string remains taut, i.e. $$a<e$$.

Summary
You are expected to know the following formulas, as they will not be provided in the examination:

title: A-level Mathematics/OCR/M3/SHM