Home

Bbc bitesize National 5 chemistry

Octopart Is The Preferred Search Engine for Electronic Parts

LM293GZ-5 National Semiconductor CAD model downloa

Metals are a widely used resource. In National 5 Chemistry learn about how different metals depending on their properties are used for different jobs National 5 Chemistry Chemical changes and structures learning resources for adults, children, parents and teachers Chemical analysis is important for checking that the environment remains healthy and safe. If pollution occurs it can be detected and monitored by chemists using a variety of techniques. There are.

An introduction to how protons, neutrons and electrons make up atoms Material sourced from BBC Bitesize Revision Website National 5 Chemistry Unit 1 Chemical changes and structures Topic Page 1 - Rates of Reaction 1 Minitest 7 2 - Elements & Atomic Structure 10 Minitest 14 3 - Bonding Related to Properties of Materials 15 Minitest 19 4 - Chemical Formulae 21 5 - Balancing Equations 2

National 5 Chemistry Revision Page 7 Unit 2 - Nature's Chemistry 2 - Nuclear chemistry Nuclear chemistry is the study of the break up of unstable nuclei, which results in the emission of radiation and the release of energy. This changes the unstable nuclei into more stable nuclei Williamwood High School My Tweets Williamwood Links. BBC Bitesize Higher Revision for SQA chemistry courses; BBC Bitesize National 4 Revision for SQA chemistry courses; BBC Bitesize National 5 Revision for SQA chemistry courses; Evans2ChemWeb Chemistry students will be given the and password. Revision notes and webtests Chemical Formulas - from BBC Bitesize - includes using the SVSDF for getting your formula BBC Bitesize Link _____ Chemical Formulas, Protons, Atoms etc - quiz to try with answer

SQA Past Papers Chemistry National 5; SQA Specimen Paper Chemistry National 5; SQA Understanding Standards Chemistry; BBC Bitesize National 5 Chemistry; What can I go on to next? If you complete the course successfully, it may lead to: Higher Chemistry; Higher Environmental Science; Further study, training or employment in: Chemical and. Posted on January 5, 2016 January 7, 2016 Tagged chemistry, christmas, christmas chemistry, combustion, complete combustion, incomplete combustion, national 4, national 5 Leave a comment Check out the site COMPOUND INTEREST - loads of really interesting everyday applications of chemistry You can now download a useful app for your iphone or ipad for revision for National 5 Chemistry. Click on the picture below to download it from the App Store APPENDIX BBC Bitesize: GCSE Chemistry Video Brief May 2017 2 About BBC Bitesize Who is the BBC Bitesize audience? itesize is the s study support ser vice for students, helping 5-16 year olds with their coursework, homework and preparation stfor tests and exams. Bitesize covers core subjects at primary, Scottish The BBC Bitesize - GCSE, Nationals and Highers app is just the one for you if you're 14-16 and studying for any of these exams. It's not intended to be used by under-13s (if this is you, check out our website at https://bbc.co.uk/bitesize instead)

The BBC has this week launched its online and TV-based teaching service under the BBC Bitesize brand. The content available may prove useful for teachers to complement existing lesson plans or study areas, or as guides for parents to engage children in learning on topics covering all areas of the curriculum Uses of Alkanes Name of Alkane Use Methane Fuel for cooking and heating Butane Used in barbecues and camping stoves Octane One of the compounds in petrol https: //www. bbc. co. uk/bitesize/guides/zw 4 tw 6 f/revision/ Ionic bonding - Bonding and properties of materials - National 5 Chemistry Revision - BBC Bitesize 2020. In-text: (Ionic bonding - Bonding and properties of materials - National 5 Chemistry Revision - BBC Bitesize, 2020) Your Bibliography: BBC Bitesize. 2020 Chemistry Revision Guides That Might Help Bbc Bitesize. National 5 Chemistry Unit 1 Chemical Changes And Structures. Chemical Equation Examples Answers. Bbc Gcse Bitesize Science Moleolar Mass Revision Page 4 Cute766. Chemistry 1 Lessons Blendspace. National 5 Chemistry Unit 1 Chemical Changes And Structures. How To Balance Chemical Equations.

Complete Past Paper Qs on all topics, available at BBC Bitesize, National 5 Modern Studies Bitesize is the BBC's free online study support Chemistry, Computing Studies, Maths, English, Modern Studies (a course exclusive to Scotland), French, Physical Education, Geography, and Physics. The site was updated in 2014 to replace the Standard Grade. National 5 Chemistry Notes. These notes come from Kelso High School. Many thanks to the staff there for creating these great resources. Unit 1 Chemical Changes and Structure. Rates of Reaction. Formulae and Equations 1. Formulae and Equations 2. Atomic Structure, Bonding and Properties. Acids and Alkalis. Moles 1 Bitesize is the BBC's free online study History, Chemistry, Computing Studies, Maths, English, Modern Studies (a course exclusive to Scotland), French, Physical Education, Geography, and Physics. The site was updated in 2014 to replace the Standard Grade section with National 4 and National 5 sections. Gaelic versions of these were. National 4/5 Chemistry - ehschem. BBC Bitesize Higher Chemistry Higher Chemistry Notes. BBC Bitesize National 5 Chemistry National 5 Chemistry Notes. Evans2 Chemweb Chemistry Revision Site. SCHOLAR SCHOLAR Website Key Area 1.3 DNA and production of Proteins. (extra explanation - too complicated for National 5 but might be of interest - Karyotype from a female human lymphocyte (46, XX). Chromosomes were hybridized with a probe for Alu sequences (green) and the rest was counterstained with TOPRO-3 (red stain)

Download BBC Bitesize - GCSE, Nationals & Highers Revision 4.1.2 latest version XAPK (APK Bundle) by Media Applications Technologies for the BBC for Android free online at APKFab.com. The BBC Bitesize - Revision app for GCSE, TGAU, National 4/5 and Highers These should be viewed along with the National 5 to Advanced Higher Course information for 2020-21. Examples of candidate evidence with commentaries. Examples of candidate evidence with commentaries; Audio Presentation. Chemistry Units: assessment and external verification (SCQF level 3 - SCQF level 7) (36.85 MB) Course assessment overvie A diatomic molecule is any molecule made up of only two atoms sharing electrons. For example, hydrogen fluoride or oxygen: There are 11 elements in the periodic table which exist as diatomic molecules: These elements are Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine and Iodine. These can be remembered as the GENuINE elements - ie. th Advanced Higher Chemistry - ehschem. Advanced Higher Chemistry. Click HERE for printable copies of your class notes. Click HERE for practice questions. Click HERE for class Powerpoints. Click HERE for course videos. Leave a Reply Cancel reply. Fill in your details below or click an icon to log in

bbc bitesize Ionic compounds. 10 terms. Joseph_Seale. bbc bitesize covalent bonds. 10 terms. Joseph_Seale. bbc bitesize Electrolysis. 10 terms. alyssaayris. Chemistry OCR A 4.1. 59 terms. Databases. National 5 Chemistry: Unit 2. 39 terms. Kirsty_Anderson1912. crude oil. 46 terms. beccawrigley. OTHER SETS BY THIS CREATOR. ICT All revision so. National 5 Chemistry. The National 5 chemistry course aims to encourage pupils to develop an understanding of chemistry's role in scientific issues whilst acquiring and applying knowledge and understanding of key chemistry concepts. Pupils will develop scientific, analytical and problem solving skills in a chemistry context The National 5 lessons on BBC Bitesize Daily Lessons cover the following subjects: Application of Maths Art and Design Biology Business Management Chemistry Computing Science Dance Design and Manufacture Drama Engineering Science English Fashion and Textile Technology French Gaelic (Learners) Geography German Graphic Communicatio S3 National 5 (Week 9 Lesson 21 Week 9 Lesson 22 Week 9 Lesson 23) S4 National 5 (22. Unit 1 Revision - Isotopes 23. Unit 1 Revision - Ions 24. Unit 1 Revision - Chemical Formula) S5/6 National 5 (12. Unit 2 Revision - Alkenes, Isomers and Addition Reactions 11. Graphs 10. Unit 2 Revision - Homologous Series) Higher (1

Chemistry National 4 and National 5 Course Textbooks Name Author Publisher Chemistry - with Answers John Anderson, Stephen Jeffery Hodder Gibson National 5 BBC bitesize Reinforce & apply knowledge and provide next level challenges evans2chemweb.co.u Rock cycle summary - The rock cycle - KS3 Chemistry Revision - BBC Bitesize. Study the effect biological, chemical and physical weathering have on the rock cycle with BBC Bitesize KS3 Science. Saved by BBC iPlayer. 5. Chemistry Revision Weathering And Erosion Fantastic Mr Fox Rock Cycle Igneous Rock Earth Science The Rock Geography Bbc BBC Bitesize. July 9, 2018 ·. In this video from GCSE Chemistry, Fran gives us a practical demonstration using electrolysis to separate substances. 66. 3 Shares Online courses for Scotland's schools and colleges. We offer 39 online courses for Scottish schools and colleges aligned to the SQA curriculum at National 5, Higher and Advanced Higher level. We draw on the knowledge and experience of teachers and lecturers working in Scottish schools and colleges to develop our course materials

All Senior phase chemistry activities are on Microsoft teams. Please log on using your school to access your learning activities. If you do not have access to your school please contact me ASAP Matthew.Hughes@castlebrae.edin.sch.uk Additional resources are on the school website powerpoints, questions and homework. Click on the following links to take yo 7 November 2017 ·. On this day in 1867, 150 years ago, Marie Curie was born. She became the first woman to win a Nobel Prize, the only woman to win twice and the only person to win in two different sciences (Physics and Chemistry). With her husband Pierre, she did some groundbreaking work investigating radioactivity and discovered the elements. Chemistry Paper 1: Atomic structure and the periodic table - elements, BBC Bitesize - Using the Earth's resources and obtaining potable water Paper 2: Using resources - Reducing pollution and recycling metals 5.10.2/Life cycle assessment and recycling national grid, electrical power and energy transfers in the hom

National 5 Chemistry - Scotland - BBC Bitesiz

BBC Bitesize. March 29, 2018 ·. This GCSE Chemistry video focuses on the periodic table, which contains all the known elements, arranged into groups and periods WeAllHaveWings Sun 26-Apr-20 15:53:52. ds and I followed an Introduction to Higher Chemistry online session last week on Scholar (Scottish curriculum, provided by our school) and it said if using the BBC Bitesize pages for Scotland be careful as they are out of date with the changes made to the SQA courses in 2018

homework and preparation for tests and exams. Bitesize covers core subjects at primary, Scottish 1st and 2nd levels, and a much wider range of subjects at secondary, including KS3, GCSE, CA3, Welsh TGAU, Scottish National 4 and 5. BBC Bitesize is used by approximately three-quarters of secondary school students in the UK, an Genetic engineering - Genetic engineering - National 5 Biology Revision - BBC Bitesize. In National 5 Biology find out more about genetic engineering and the transfer of DNA from one organism to another naturally and using biotechnology. Saved by Eldridge. 4 CONTENT BRIEF KS3 PHYSICS VIDEOS Page 3 Content brief The brief is to produce 12 short films, plus 1 short social trailer, to support KS3 students (age 11 - 14) studying Physics. The films will sit within a suite of new Bitesize articles also including text, infographics, archiv Domain name system bbc bitesize. By submitting a whois query you agree that you will use this data only for lawful purposes and that under no circumstances will you use this data to. The resolving name server is the second step after the local dns cache. Charles darwin developed the theory of evolution by natural selection Primary Programme 26. BBC Bitesize. Duration: 25 minutes. First broadcast: Mon 22nd Feb 2021, 10:00 on BBC Scotland Latest broadcast: Fri 26th Mar 2021, 10:00 on BBC Scotland. Available for 8 months

National 5 Chemistry Revision - BBC Bitesiz

Writing in Specific Forms (BBC Bitesize): Imaginative / Script / Newspaper Report. Writing Accuracy (LT Scotland): Knowledge of Language. Writing Style (BBC Bitesize): Figurative Language. Writing Style (BBC Learning Video): Sentence Construction. Writing Exams (SQA Understanding Standards): Example Essays / Marks Mars Rover Curiosity Sees Key Water Indicator - Bbc News Source: www.bbc.co.uk Bbc Bitesize - Ks3 Maths - Time - Revision 3 Source: www.bbc.co.uk Sample Space Diagram World Of Diagrams Source: www.6aming.com Bbc Bitesize - National 5 Geography - Urban Environments Source: www.bbc.co.uk Sean Paul - Acts - 1xtra Live 2013 - Leeds / Londo BBC Bitesize. June 12, 2018 ·. What sort of energy changes are involved in chemical reactions? This video from Bitesize GCSE Chemistry provides a handy way to tell the difference between endothermic and exothermic reactions. 1010 Past papers and marking instructions. Find past papers and marking instructions for your revision. You can search by topic and or refine by subject and level. To add the matching marking instructions simply tick the box. Please note that because of copyright we can only provide up to five years of past papers BBC - Bitesize KS2 - Games - Questionaut BBC - Bitesize KS2 - Games - Questionaut: 'via Blog this' Park Lines | National Parks News and Alerts from N... Monthly Historical Events In Chemistry; Welcome to the Crestwood-Antarctica Connection! -.

Saved from bbc.com. The human gas exchange system - Respiration - KS3 Biology Revision - BBC Bitesize. Study the difference between aerobic and anaerobic respiration and how the human gas exchange system works. Saved by Jojo T. 1. Biology Revision Science Revision Ribs Respiratory System Breath In Breath Out Moving Out Rib Cage Aerobics BBC Bitesize KS3 Chemistry The formation of sedimentary rock Renewable Energy Explained in 2 1/2 Minutes alongside the BBC Bitesize collection of educational... Scotland), including those studying for GCSE and National exams. On TV, there are Lockdown Learning: What educational resources are on TV, iPlayer and online? Page 14/26 Definition of development bbc bitesize. Learn about sustainable development with bitesize gcse chemistry aqa. Add to my bitesize. Essay bbc bitesize globalisation essay pdf. Metier d essayiste history essays past or present tense example of case study nursing 1000 word essay on shaving • BBC Bitesize supports students with their studies outside the classroom, at Updates to National 5 English Updates to Higher English, Maths, Biology, Chemistry, Physics, Computing Science, Chemistry In production 18/19 KS3/CA3 - Chemistry, Physics, Biology. CA3 Maths, KS3 Welsh Second Language,. <p>Valence electrons can move from one atom to another creating a cloud of delocalized electrons. Electrons are also affected by magnetic fields so when a metal is moved in a magnetic field, the delocalised electrons all tend to move in the same direction - this is how a generator or dynamo works. </p> <p>STUDY. </p> <p>Methane is formed from one carbon atom and four hydrogen atoms. Understand.

National 5 Chemistry - BBC Bitesiz

  1. Art and Design: Expressive Activity (SCQF level 5) Modifications for session 2021-22 will remain the same as session 2020-21. Outcome 2. Assessment standard 2.2: we will reduce the number of analytical drawings and/or studies required from three to two
  2. Study the different types of fuel resources like fossil, nuclear, wind, wave and solar power with BBC Bitesize KS3 Science Food, oil, coal, gas, petrol, turf and wood are some of the resources which supply chemical energy. Kinetic energy is an energy form. Waves, tides, wind and falling water are some of the resources.
  3. In National 4 Geography revise geology and sea level changes, how coastal features are formed and why land uses at the coast can lead to conflict
  4. National 4 Chemistry - Scotland - BBC Bitesize File Name: National 4 5 Chemistry Revision Notes Largs Academy.pdf Size: 5512 KB Type: PDF, ePub, eBook Category: Book Uploaded: 2020 Nov 20, 19:22 Rating: 4.6/5 from 853 votes

Get Free Answers To Revision Questions For Higher Chemistry Financial Management revision questions and answers Revise and learn what fractions are and how to order, add, subtract, multiply and divide fractions and work out common factors with BBC Bitesize KS3 Maths Revise and learn what fractions are and how to order, add, subtract, multiply and divide fractions and work out common factors with BBC Bitesize KS3 Maths. Fractions test questions - KS3 Maths Revision - BBC Bitesize Full coverage of physics revision questions for the 2018 onwards syllabus. All questions are set primarily by topic, not by paper Higher ChemistryAnswers To Revision Questions For Higher Chemistry Getting the books answers to mathOgenius Going from grade 5 to grade 9: AQA English Language Paper 1 Q2 (2018 exam) Real UK BBC Bitesize Class 6 Mathematics Get revision Page 5/13. Download Ebook Answer

Chemistry in society - Metals - National 5 - BBC Bitesiz

  1. A test for the AQA Unit 5.9 Chemistry of the Atmosphere. The test questions are based on AQA past exam papers and can be matched up to the Student Progress Sheet to enable students and teachers to identify areas for improvement.Tags in this resource: CO2-Gas-Gr
  2. What is BBC Bitesize? BBC Bitesize is for 14-16 year olds in England, Northern Ireland, Scotland and Wales. It contains subjects for GCSEs, National 4, National 5, Higher and TGAU. BBC Bitesize has all the info you need to prepare for math, English, and other exams you may need to pass

Chemical changes and structures - National 5 Chemistry

  1. g Polymers; Week 2 lesson 5 The problem with plastics; Week 2 lesson 6 pollution) S5/6 National 5 (S5-6 lockdown 2, week 2
  2. Advanced Higher Biology. This course contains 3 units: Each unit will be assessed continually in class, through the use of past paper based homework and an A-D level class test and SQA assessment. The Advanced Higher Biology Course focuses on the areas of cells and proteins, organisms and evolution, and investigative biology
  3. Here you can find links to websites and documents which will help you in your Higher Chemistry studies. Introduction: Learning Outcomes 2018: Data Booklet: Introduction. Outcomes. Data booklet. Higher BBC Revision: Scholar: Past Papers: Higher Chemistry. Unit 1. 2017 Question paper. 2017 answers. Unit 2. 2016 question paper. 2016 answers. Unit.
  4. The most-watched GCSE Science revision videos covering Biology, Chemistry and Physics
  5. Digital Learning Newsletter January 2021 - The purpose of this newsletter is to give you further up to date advice on remote learning and share some information, some useful hints and tips and also point out some of the pitfalls with you.. Online Safety Policy - Westhill Academy. Westhill Academy Twitter account. Introduction. Below, you will find information on:
  6. CRC Handbook of Chemistry and Physics (79th Ed) 3. The Periodic Table 4. CRC Handbook of Chemistry and Physics (79th Ed) 5. Barron's How to Prepare for the Sat II Chemistry (6th Ed) 6. Chemistry : Concepts and Problems : A Self-Teaching Guide (Wiley Self-Teaching Guides) 7

Getty Images. Online - learning resources for children of all ages can be found on the BBC Bitesize website. TV - programming for primary school pupils is on CBBC between 09:00 and 12.00 every. This fantastic set of mindfulness colouring sheets are a great way of helping your children - and yourself! - de-stress and calm down. Perfect for those trying days!Looking for something easier for the kids? Try our sports colouring page, or this Girl Running with Football Colouring Sheet! There is also our Winners Podium Worksheet. The Naked Scientists, online, internet science radio show and podcast. Science articles, science discussion forum, interviews with famous scientists, free audio downloads and kitchen science experiments

Chemical analysis - Chemical analysis - National 5 - BB

BBC Music - The destination for curious music lover The materials below should therefore be viewed along with the National 5 to Advanced Higher Course information for 2020-21. Examples of candidate evidence with commentaries. Examples of candidate evidence with commentaries; Course assessment overview. Overview of Course Assessment Presentation with audio June 2018 (7 minutes and 40 seconds) (12.

Atoms and isotopes - National 5 Chemistry - BBC Bitesiz

  1. Economic factors - External factors - National 5 Business management Revision - BBC Bitesize - Read online for free. Scribd is the world's largest social reading and publishing site. Open navigation men
  2. Economics Revision. You can find summary notes and past papers for each of the modules and exam boards below
  3. ‪Circuit Construction Kit: DC - Virtual Lab
  4. The Nrich Maths Project Cambridge,England. Mathematics resources for children,parents and teachers to enrich learning. Problems,children's solutions,interactivities,games,articles
  5. BBC Bitesize Scotland Weekly Schedule Resource Plans. During periods of remote learning, BBC Scotland are running a number of Daily Bitesize programmes to support the learning of Scotland's children. These schedules link Twinkl resources to BBC Scotland's daily programmes by subject area and appropriate age group
Timeline | Chemistry Department

BBC Bitesize KS3 Chemistry Collision theory and how to speed up rates of reaction. Collision Theory Essay #2 BB - StuDocu. National 5: Collision Theory - YouTube This video looks at basic collision theory. This is the theory that allows us to predict how fast a reaction will go and how to change the rate of reaction... Metals Revision 1 National 5 Chemistry BBC Bitesize April 17th, 2019 - Chemistry in society Metals Every metal conducts electricity This is due to the metallic bonding found within metal elements In metallic bonding the outer electrons are delocalised free to move 1 AQA Revision Guides chemrevise April 13th, 2019 - New A level 2015 The revisio You searched for bbc ks2 bitesize science p.Showing 85 - 96 of 42533 results Avoid resits and achieve higher grades with the best study notes available for Other at the Othe qatar in biology physics math chemistry english and ict, ocr is a leading uk awarding body providing qualifications for learners of all ages at school college in work or through part time learning programmes, schoolexams co uk is the 1 online site for edexcel gcse english and maths past paper

Course notes and resources Chemistry Departmen

Chemistry Class Book Spectrum Key Stage 3 Science How your Page 4/28. Online Library Key Stage 3 Science Classbook Key Stage 3 Classbooks digestive system works - Emma Bryce BBC bitesize forces - KS3 12. BBC Bitesize KS3 Revision Electricity and Magnetism BBC18LS12 The Earth's Structure - National Curriculum in Science in short engaging. 2002 ( MMII) was a common year starting on Tuesday of the Gregorian calendar, the 2002nd year of the Common Era (CE) and Anno Domini (AD) designations, the 2nd year of the 3rd millennium, the 2nd year of the 21st century, and the 3rd year of the 2000s decade. Calendar year SQA Higher Biology Unit 1 (DNA and the Genome) Cue Cards Last document update: ago. Cue cards created from my class notes and BBC Bitesize. Also available: unit 2, unit 3, all units, free preview. $9.11. Add to cart. Show more info. SQA Higher Biology Unit 2 (Metabolism for Survival) Cue Cards SECTION ALSO INCLUDES SQA NATIONAL 5 CHEMISTRY PAST PAPERS' 'AMAZON COM EDEXCEL CHEMISTRY MAY 11TH, 2018 - NEW GRADE 9 1 EDEXCEL INTERNATIONAL GCSE CHEMISTRY REVISION GUIDE WITH ONLINE EDITION JUN 16 2017 BY CGP BOOKS 'BBC Bitesize GCSE Chemistry Single Science Edexcel May 13th, 2018 - The 9 1 Edexcel Specification For GCSE Chemistry.

Chemistry KS4/GCSE: How are plastics made? - BBC Teach

National 5 - Scotland - BBC Bitesize 2,8,8 is the electron arrangement for an atom of an element belonging to the B c transition metals. An atom is neutral because National 5 Chemistry Past Paper Revision Questions National 5: Functions Revision 2006 P1 2 Ans -5 2003 P1 1 2 Ans (a) 15 (b) -0.5 2002 P1 2 Ans -6 2001 P1 2 Ans 40 2000 P1 2 Ans. KS3 Science - BBC Bitesize Testbase has the complete SATS past papers (national curriculum tests) to download here free of charge, including English KS1-3, Maths KS1-3 & Science KS2-3 National curriculum past papers - 2003-2019 | Testbas

National 5 Chemistry - Biology and Chemistry Tuitio

BTEC Applied Science Unit 1 Chemistry Flashcards | Quizlet Apr 20, 2017 · This resource is designed for Level 3 students sitting the Edexcel Applied Science 2016 course Btec applied science level 3 unit 1 exam questions. The guide covers all of Unit 1, Learning Aims A, B and C (Chemistry, Biology and Physics) examination content BBC Bitesize KS3 Chemistry Mixtures and compounds Elements and atoms | Atoms, compounds, and ions | Chemistry | Khan Academy 8. BBC Bitesize KS3 Elements, Compounds \u0026 Mixtures BBC18LS08 Atoms, Elements \u0026 Compounds | Atomic Structure | GCSE Chemistry (9-1) Dave SmartRevise Seneca BBC Bitesize The Everlearner Grok Learning GCSE Computer Science OCR Complete Revision & Practice - for exams in 20212 and over Food & NUTRITION AQA 8585 Exam board website Unit 1 (written card) - 50% Unit 2 (controlled evaluation - design and practice) - 50% I-revise food forum 30-35 hours (100 signs

BBC - Standard Grade Bitesize Chemistry - FertilisersExam | Chemistry DepartmentBBC Bitesize - National 5 Chemistry - Chemical formulae