OpenLLM-France/wikimedia huggingface dataset:
# A-level Chemistry/OCR (Salters)/Colour by Design/Check Your Notes/Absorption of Ulraviolet Light

Atoms contain electrons. When an atom is not in an excited state, the electrons have the lowest possible energy. This is known as being in ground state. Electrons can have an infinite number of discrete energy levels. If one visulises theses levels as concentric circles around a nucleus they begin to converge, as every step between energy levels gets smaller.
"http://i89.photobucket.com/albums/k213/blackcurrent_jelly/rt.jpg"
The diagram is very basic as electrons can possess many more levels than shown.
The distance between each energy level corresponds to the amount of energy an electron needs to be given to 'jump' to it. Once an electron has been excited to an energy level is does not remain there unless continually being supplied with the required energy, instead it emits the energy is was given, and jumps back down to ground state. Electrons require a specific frequency of energy to excite up a level.
Visible light is made up of many different frequencies. If an atom absorbs absorbs its required certain frequency of energy from visible radiation (light) an electron is promoted from ground state to one of several possible levels; the atoms is in an excited state. It does not remain excited for long, as the energy absorbed is re-emitted as the frequency it absorbs, producing light of the colour related to the frequency.
It must be noted that when a molecule becomes excited, it can drop to an intermediate energy level by releasing a smaller packet (quanta) of energy and loosing the rest via vibrational energy in collisions. This vibrational energy is converted into kinetic energy and molecules in a sample will move more vigorously causing the sample to become warm.
# A-level Chemistry/OCR (Salters)/Designer Polymers

Designer Polymers is the seventh unit in the Salters Advanced Chemistry course.

## Chemical Storylines sections

* DP1 Designer polymers
* DP2 The invention of nylon
* DP3 Polyesters: from clothes to bottles
* DP4 Kevlar
* DP5 Taking temperature into account
* DP6 Poly(ethene) by design
* DP7 Throwing it away... or not?
* DP8 Summary

## Chemical Ideas sections

* 5.4 Forces between molecules: hydrogen bonding (revision)
* 5.5 The structure and properties of polymers
* 13.3 Carboxylic acids and their derivatives (revision)
* 13.4a,b The –OH group in alcohols, phenols and acids (revision)
* 13.5 Esters (part revision)
* 13.8 Amines and amides

## Activities

* DP2.1 Making nylon
* DP2.2 Taking nylon apart
* DP4 Comparing models of nylon–6,6 and Kevlar
* DP5 Bubble gum - or bubble glass?
* DP8 Check your notes on Designer Polymers

## External links

* DP unit map
* DP Check Your Notes
# A-level Chemistry/OCR (Salters)/Colour by Design/Check Your Notes/Colour Changes Associated With Chemical Changes

Colour change associated with Ligand Exchange reactions: When ligands are formed around a metal ion (e.g. [Fe(H2O)6]) it is known as a complex. The coordination number of a complex denotes how many ligands are attached to the central ion, it is usually 4 or 6. There are 3 types of shapes associated with complexes:
- Square Planar (coordination number, 4)
- Tetrahedral (coordination number, 4)
- Octahedral (coordination number, 6)
When complexes are formed the electrons delocalise within the molecule and this allows the complex to absorb certain frequencies of light. The frequency depends upon the type of central ion, the ligands and the shape of the complex. When the light is absorbed the electrons in the D-orbital split into 2 groups. This allows the light to be absorbed. If the frequency of the light absorbed is 450 nm it means that red light is absorbed, if the red light is absorbed it means the blue light is reflected, and this is the colour seen to the human eye.
(Edited by Andy Richardson and Harry Alexander)
# A-level Chemistry/OCR (Salters)/Elements from the Sea

From Minerals to Elements is the third unit in the Salters Advanced Chemistry course.

## Chemical Storylines sections

* ES1: Why is the sea so salty? A story of smokers and solutions
* ES2: The lowest point on Earth
* ES3: An industrial case study - how best to manufacture chlorine?
* ES4: From atomic bombs to safer drinking water
* ES5: Hydrochloric acid - an industrial success
* ES6: Treasures os the sea
* ES7: Summary

## Chemical Ideas sections

* 5.1: Ions in solids and solutions
* 9.1: Oxidation
* 2.4: Electronic structure: sub-shells and orbitals
* 11.4: The p-block: Group 7
* 1.5: Concentrations of solutions
* 8.1: Acid-base reactions
* 5.2: Molecules and networks

## Activities

* M1.1: Solutions of ions
* M1.2: Bromine production
* M1.3: Halogens and their compounds
* M1.4: This liquid is dangerous
* M1.5: Manufacturing chlorine
* M2.1: Mineral spotting
* M2.2: Getting at the minerals
* M2.3: Extracting copper
* M2.4: Finding out how much acid there is in a solution
* M2.5: The philosopher’s microbe?
* M2.6: Molecules and networks
* M3: Check your notes on From Minerals to Elements

## External links

* M unit map
* M Check Your Notes
# A-level Chemistry/OCR (Salters)/Colour by Design/Check Your Notes

Colour By Design!
What you should know!!
* Absorption of ultraviolet light and visible light in terms of transitions between electronic energy levels.
* Use of ultraviolet (u.v.) and visible spectroscopy to help identify unsaturated organic molecules.
* Colour changes associated with the following types of chemical changes: acid-base (indicators), ligand exchange, redox, precipitation and polymorphism (different crystal structures).
* The relationship between the properties of pigments (colour shade, colour intensity, fastness) to relevant properties (Storyline CD2 and CD3).
* General principles of gas-liquid chromatography (g.l.c.)
* Techniques used to identify the materials used in a painting, including the use of g.l.c. atomic emission spectroscopy, visible spectroscopy (reflection and transmission) (Storyline CD3 and CD4; Activities CD4.1 to CD4.5).
* Nature of fats and oils as mixed esters of propane-1,2,3-triol with varying degrees of unsaturation.
* An outline of the process of oxidative cross-linking by which unsaturated oils harden; the relationship of this process to their use as media in oil-based paints.
* What arenes and arene derivatives (aromatic compounds) are.
* Structure of benzene.
* How the characteristic properties of aromatic compounds arise from the delocalisation of electrons.
* Following electrophilic substitution reactions of arenes: halogenation of the ring, nitration, sulphonation, Friedel-Crafts alkylation and Friedel-Crafts acylation.
* Formation of azo dyes by coupling reactions involving diazonium compounds.
* Structure of a dye molecule in terms of its various components: chromophore, groups which modify the chromophore, groups which made the dye more soluble in water and groups which attach the dye to the fibre (Storyline CD5 to CD7).
* Ways in which dyes attach themselves to fabrics: weak intermolecular forces, hydrogen bonds, ionic attractions and covalent bonding (Storyline CD7; Activity CD7.2).
* Relationship between the colour of a dye and the presence of a chromophore, and groups that modify the chromophore, in the dye molecule.
* Relationship between colour in materials and transitions between electronic energy levels.
# A-level Chemistry/OCR (Salters)/Constants

| Constant | Symbol for constant | Value | Unit(s)* | Symbol for unit(s) |
| Avogadro's number | L | 6.02 × 10$^{23}$ | mol$^{−1}$ | reciprocal moles |
| Planck's constant | h | 6.63 × 10$^{−34}$ | J Hz$^{−1}$ | joules per hertz |
| speed of light | c | 3 × 10$^8$ | m s$^{−1}$ | metres per second |
* Note that SI units are shown in bold
# A-level Chemistry/OCR (Salters)/Electronic configurations
## Period 3 transition metals

All these elements have electron configurations that begin 1s$^2$ 2s$^2$ 2p$^6$ 3s$^2$ 3p$^6$ but they have different 3d and 4s subshells. 1s$^2$ 2s$^2$ 2p$^6$ 3s$^2$ 3p$^6$ is the electronic configuration of argon, so instead of writing this out over and over again, it's neater to write [Ar], which means the same thing.
All these d-block metals follow the same pattern, with the 4s subshell filled and the 3d subshell filling, except Cr and Cu which are 4s$^1$ in order to allow a half-full and full 3d subshell, respectively. The exception for chromium and copper occurs because a half-full or full 3d subshell is lower in energy than expected, probably due to a quantum mechanical effect.
| Element | Proton number | Electron configuration |
| Sc | 21 | [Ar] 3d$^1$ 4s$^2$ |
| Ti | 22 | [Ar] 3d$^2$ 4s$^2$ |
| V | 23 | [Ar] 3d$^3$ 4s$^2$ |
| Cr | 24 | [Ar] 3d$^5$ 4s$^1$ |
| Mn | 25 | [Ar] 3d$^5$ 4s$^2$ |
| Fe | 26 | [Ar] 3d$^6$ 4s$^2$ |
| Co | 27 | [Ar] 3d$^7$ 4s$^2$ |
| Ni | 28 | [Ar] 3d$^8$ 4s$^2$ |
| Cu | 29 | [Ar] 3d$^{10}$ 4s$^1$ |
| Zn | 30 | [Ar] 3d$^{10}$ 4s$^2$ |

### Transition metal ions

The electronic configurations of transition metal ions can seem counter-intuitive. For neutral transition metal atoms, the 4s subshell fills first, followed by the 3d subshell, which we assume is because 3d is slightly higher in energy than 4s.
However, in transition metal ions, the 4s empties first, which implies that it is higher in energy than the 3d. So which is higher in energy, 3d or 4s? The answer is they are very close in energy, and changing from a neutral atom to an ion causes the 3d to decrease in energy relative to the 4s, meaning that in ions, the 4s empties first, whereas in neutral atoms, the 4s fills first.
| Species | Proton number | Electron configuration |
| Ti | 22 | [Ar] 3d$^2$ 4s$^2$ |
| Ti$^+$ | 22 | [Ar] 3d$^2$ 4s$^1$ |
| Ti$^{2+}$ | 22 | [Ar] 3d$^2$ |
| Ti$^{3+}$ | 22 | [Ar] 3d$^1$ |
| Ti$^{4+}$ | 22 | [Ar] |
# A-level Chemistry/OCR (Salters)/Condensation reactions

A condensation reaction is a reaction in which two molecules combine to form one molecule, eliminating a small molecule, such as HCl or H$_2$O, in the process.

## Peptide bond formation

Two amino acids can react with one another to form a dipeptide, linked by a peptide bond. A peptide bond is nothing more than a secondary amide functional group linking two amino acid residues. A water molecule is eliminated as a result.
In the illustrations below, two glycine molecules undergo condensation to form GlyGly (glycylglycine or 2-(2-aminoethanamido)ethanoic acid), expelling a water molecule.
# A-level Chemistry/OCR (Salters)/Developing Fuels

Developing Fuels is the second unit in the Salters Advanced Chemistry course.

## Chemical Storylines sections

* DF1: Petrol is popular
* DF2: Getting energy from fuels
* DF3: Focus on petrol
* DF4: Making petrol − getting the right octane rating
* DF5: Trouble with emissions
* DF6: Tackling the emissions problem
* DF7: Changing the fuel
* DF8: Hydrogen − a fuel for the future?
* DF9: Summary

## Chemical Ideas sections

* 4.1 Energy out, energy in
* 1.3 Using equations to work out reacting masses
* 4.2 Where does the energy come from?
* 12.1 Alkanes
* 3.4 Structural isomerism
* 13.2 Alcohols and ethers
* 4.3 Entropy and the direction of change

## Activities

* DF1.1 Which fuel for the future?
* DF1.2 Measuring the enthalpy change of combustion of different fuels
* DF1.3 Comparing the enthalpy changes of combustion of different alcohol
* DF2.1 Using spreadsheets to calculate enthalpy changes of combustion
* DF2.2 Making notes
* DF3.1 How do physical properties change along the alkane series?
* DF3.2 Comparing winter and summer petrol blends
* DF3.3 Auto-ignition in a test-tube
* DF4.1 Modelling and naming alkanes
* DF4.2 The octane numbers of different alkanes
* DF4.3 Using zeolites
* DF4.4 Cracking alkanes
* DF4.5 A closer look at alcohols
* DF4.6 Blend your own
* DF4.7 Why do hydrocarbons mix?
* DF4.8 Petrol - pulling it all together
* DF5 What happens to the sulphur?
* DF9 Check your notes on Developing Fuels

## External links

* DF unit map
* DF Check Your Notes
# A-level Computing/AQA/Problem Solving, Programming, Data Representation and Practical Exercise/Skeleton code/2011 Exam/Random functions

When we are making the cricket game we are allow the user to use their own die or a random number die built into the program. We are now going to look how the random number feature works:
To start using random numbers are need to set up the randomize function. This is a little like throwing a million dice in the air at once and storing all their results, we can then use these 'random' results in our program
The next thing we need to do is to allocate a number from one to six for the dice role. Remember we have two dice, one for the bowler and once for the batter:

## Assigning a random number

To get a random number we use the Rnd function (remember a function returns a value). Unfortunately the Rnd function returns a value between 0.000000 and 0.9999999. So we need to convert this to a number between 1 and 6.
To do this, we can multiply the number by 6, this will give us values between 0.00000 and 5.99999. These are obviously not whole numbers so we need to round them off to be integers Using the Int function. Giving us a number between 0 and 5. Still not perfect as we need something between 1 and 6.
So we need to be a little smarter and add 1. This will now give us a number between 1 and 6.
# A-level Computing/AQA/Problem Solving, Programming, Data Representation and Practical Exercise/Problem Solving/Decision tables

Decision tables are compact and precise ways of modelling complicated logic, such as that which you might use in a computer program. They do this by mapping the different states of a program to an action that a program should perform. Decision tables take on the following format:
The four quadrants :
| Conditions | Condition alternatives |
| Actions | Action entries |
The limited-entry decision table is the simplest to describe. The condition alternatives are simple Boolean values, and the action entries are check-marks, representing which of the actions in a given column are to be performed.
A technical support company writes a decision table to diagnose printer problems based upon symptoms described to them over the phone from their clients. They type the following data into the advice program:
* Printer does print
* Red light is flashing
* Printer is recognised
The program then uses the decision table to find the correct actions to perform, namely that of Check / Replace ink.
Printer troubleshooter :
| | | Rules | Rules | Rules | Rules | Rules | Rules | Rules | Rules |
| Conditions | Printer does not print | Y | Y | Y | Y | N | N | N | N |
| Conditions | A red light is flashing | Y | Y | N | N | Y | Y | N | N |
| Conditions | Printer is unrecognised | Y | N | Y | N | Y | N | Y | N |
| Actions | Check the power cable | | | X | | | | | |
| Actions | Check the printer-computer cable | X | | X | | | | | |
| Actions | Ensure printer software is installed | X | | X | | X | | X | |
| Actions | Check/replace ink | X | X | | | X | X | | |
| Actions | Check for paper jam | | X | | X | | | | |
Example: Decision Tables
Let's take a look at a computer game example, for a football simulation the following rules are set up.
Rules
Conditions90 minutesYYY
Team A WinningY
Team B WinningYY
DrawY
ActionsGame OverXX
Team A WinsX
Team B WinsX
Extra TimeX
Keep PlayingXX
What happens when:
90 minutes up
the game is a draw
Answer: Keep Playing and give them some extra time :
Exercise: Decision Tables
Create a decision table for the following program in an office email system
Send email when Recipient address present, subject present, before 5:30pm
If after 5:30pm then put in pending folder
If Recipient address missing or subject message, give warning message
Answer:
This question is open to interpretation, but you should have something resembling this:
Rules
ConditionsAddress PresentYYY
Subject PresentYYY
Before 5:30YYY
ActionsSend MailX
Error MessageXX
Make pendingX
Describe the use of Decision Tables
Answer:
Determine logical conditions and consequential actions. :
# A-level Computing/AQA/Problem Solving, Programming, Data Representation and Practical Exercise/Skeleton code

The exam questions are very hard to predict and this site is by no means going to give you everything you need for the questions you'll sit. The most important thing you should do is learn how to program, and learn how to program well!
* 2017 Exam
* 2016 Exam
* 2015 Exam
* 2014 Exam
* 2013 Exam
* 2012 Exam
* 2011 Exam
# A-level Computing/AQA/Problem Solving, Programming, Data Representation and Practical Exercise/Problem Solving/Structure charts

A Structure Chart in software engineering is a chart which shows the breakdown of a system to its lowest manageable parts. They are used in structured programming to arrange program modules into a tree. Each module is represented by a box, which contains the module's name. The tree structure visualizes the relationships between modules, showing data transfer between modules using arrows. Structured Charts are an example of a top-down design where a problem (the program) is broken into its components. The tree shows the relationship between modules, showing data transfer between the models.
| Symbol | Name | Meaning |
| Module Name | Process | Each Box represents a programming module, this might be something that calculates the average of some figures, or prints out some pay slips |
| | Data Couple | Data being passed from module to module that needs to be processed. |
| | Flag | [Extension - you don't need to know this for the exam] Check data sent to process to stop or start processes. For example when the End of a File that is being read is reached, or a flag to say whether data sent was in the correct format |
Let's take a look at a simple example of how this might be executed when representing the following code:
* Exercise: Structure Charts
* Create structure charts for the following code:
* sub main
* dim num1 as integer
* dim num2 as integer
* dim avg as integer
* sayHello
* num1 = 34
* num2 = 89
* avg = average(num1, num2)
* end sub
* function average(a,b)
* return (a + b) / 2
* end function
* sub sayHello
* console.writeline("hello")
* end sub
* Answer:

## Selection

A selection in a Structure Chart is determined by the diamond symbol. This means a condition will be checked and depending on the result, different modules will be executed.

## Iteration

Using the semi circular arrow we can represent iteration in Structure Charts. The arrow encompasses a link to a module, implying that module is executed multiple times. Let's take a look at a coded example:
* Exercise: Structure Charts, Iteration and Selection
* Create structure charts for the following code:
* sub howManyThrees
* dim num1, count, total as integer
* num1 = startMsg
* count = 0
* total = 0
* while num1 > 0 do
* checkNumber(count, total, num1)
* num1 = num1 - 1
* end while
* endMsg(count)
* end sub
* sub checkNumber(byRef c, byRef t, byVal n)
* If n MOD 3 = 0 Then
* c = divBy3(c)
* Else
* t = add(n, t)
* EndIf
* end sub
* function divBy3(x)
* return x + 1
* end function
* function add(n, t)
* return n + t
* end function
* function startMsg
* console.writeline("program started, enter your number")
* return console.readline
* end function
* sub endMsg(n)
* console.writeline("number of threes : " & n)
* end sub
* Answer:
# Beginners Guide to Ladino/Adjectives in Ladino
### Agreement

It is important that adjectives agree. What is agreement? Agreement is when a noun has the same gender and number as the noun it describes.
# Beginners Guide to Ladino/Nouns in Ladino
### Nouns: Gender

It is important to know the gender of nouns in Ladino so that the correct adjectives can be used with the noun. It is very simple to know if a noun is masculine or feminine with a few rules:
- Nouns ending in -or, such as kalor (heat) and kolor (color) are feminine.
- Nouns ending in -a such as klima (climate) and planeta (planet) are feminine.
- Most place names such as Ungaria (Hungary) will be feminine, as they end in -a.
- Everything else is masculine.
# Beginners Guide to Ladino/Verbs in Ladino
## Present

| | -ar verbs (avlar) | -er verbs (komer) | -ir verbs (bivir) |
| yo | -o (avlo) | -o (komo) (bivo) | -o (komo) (bivo) |
| tu | -as (avlas) | -es (komes) (bives) | -es (komes) (bives) |
| el eya | -a (avla) | -e (kome) (bive) | -e (kome) (bive) |
| mozotros | -amos (avlamos) | -emos (komemos) | -imos (bivimos) |
| vozotros | -ash (avlash) | -ésh (komésh) | -ísh (bivísh) |
| eyos | -an (avlan) | -en (komen) (biven) | -en (komen) (biven) |

## Preterite

In Ladino, the preterite indicates that an action taken once in the past was also completed at some point in the past. This is as opposed to the imperfect tense which refers to any continuous, habitual, unfinished or repetitive past action. Thus, "I ate falafel yesterday" would use the first-person preterite form of eat, comí, whereas "When I lived in Izmir, I ran five miles every evening" would use the first-person imperfect tense form, koría. Though some of the morphology has changed, usage is just as in normative Castilian.
Typical conjugation:
| | -ar verbs (avlar) | -er verbs (komer) and -ir verbs (bivir) |
| yo | -í (avlí) | -í (komí) (biví) |
| tu | -ates (avlates) | -ites (komites) (bivites) |
| el eya | -ó (avló) | -yó (komyó) (bivyó) |
| mozotros | -amos (avlamos) | -imos (komimos) (bivimos) |
| vozotros | -atesh (avlatesh) | -itesh (komitesh) (bivitesh) |
| eyos | -aron (avlaron) | -yeron (komyeron) (bivyeron) |
# Beginning Java

The Java programming language is used widely in education and industry, and is a great choice as a first programming language.
The aim of this book is to provide a starting point for readers not only new to Java but to programming in general in a progressive order with examples they can follow.

## Contributing
### Editors/Writers

If you want to edit or contribute, feel free to dig in and start editing, you are entirely encouraged to be bold.

### Readers

For those who don't know Java and wish to learn, or are simply interested in Java, feedback is requested and much appreciated.

## Contents

Table of Contents

### Preface

* Java Overview
* History of Java
* Applications of Java

### Part I

* Machine Setup
* First Program
* Variables
* Conditionals
* Loops
* Methods
* Objects
* Scope

### Part II

* Best Practices
* Variables 2
* Boolean Logic
# Beginners Guide to Ladino/Ladino Grammar
### Ladino Grammar

Ladino grammar functions very similarly to Spanish, although according to many linguists their grammar is actually closer to Galician and Portuguese rather than Spanish.
Here are the Pronouns in Ladino and English, we will start with: I/me, you, he, they (masculine), you guys (masculine), we (masculine)
| English | Ladino |
| I | Yo (ייו) |
| You (singular) | Tu (טו) |
| He | El (איל) |
| She | Ella (אילייה) |
| They (masculine) | Ellos (ֵאילייוס) |
| They (feminine) | Ellas (ֵאילייאס) |
| We (masculine) | Mozotros (מוזוטרוס) |
| We (feminine) | Mozotras (מוזוטראס) |
| You (plural masculine) | Vozotros (בֿוזוטרוס) |
| You (plural feminine) | Vozotras (בֿוזוטראס) |
Note:
[1] The "double L" <ll> is pronounced as a <y>. As mentioned in the Guide to Reading and Writing Ladino. The double "ll" is written as <ליי> with the <ל> being silent. The "double L" is only used in certain dialects but all dialects use it to spell ellos, ellas, and ella.
[2] For the plural pronouns (mozotros, vozotros, and ellos) the masculine form is used to show a group of not just men but also both men and women in one group while the feminine form is only used for a group of only females.
# Beginning Java/First Program
## HelloWorld.java

Code:
Output: