Published forOXFORD INTERNATIONALAQA EXAMINATIONSInternational A LevelCHEMISTRYAS andA LEVELTed ListerJanet RenshawOXFORDPublished forOXFORD INTERNATIONALAQA EXAMINATIONSInternational A LevelCHEMISTRYAS andA LEVELTed ListerOXFORDJanet RenshawUNIVERSITY PRESSOXFORDUNIVERSITY PRESSGreat Clarendon Street,Oxford,OX2 6DP.United KingdomAcknowledgementsThe publishers would like to thank the following for permissionsOxford University Press is a department of the University ofto use their photographs:Oxford.It furthers the University's objective of excellence inresearch.scholarship,and education by publishing worldwide.Cover:Francisco Chanes/Custom Medical StockOxford is a registered trade mark of Oxford University Press inPhotoScience Photothe UK and in certain other countriesp17:John Mclean/Science Photo Library:p19:Jpl-Caltech/Msss/Ted Lister and lanet Renshaw 2016NASA:p32:Martyn Chillmaid;p36:Hulton-Deutsch Collection/Corbis;p40:Martyn Chillmaid;p70:Nicolas/iStockphoto:p81:The moral rights of the authors have been assertedMartyn F.Chillmaid/Science Photo Library;p89:Martyn F.First published in 2016Chillmaid:p111t:Shutterstock:p111b:Shutterstock:p117:Science Photo Library:p120:Science Photo Library:p147:All rights reserved.No part of this publication may beScience Photo Library:p160:Andrew Fletcher/Shutterstock:;reproduced,stored in a retrieval system,or transmitted,in anyp163t:Green Gate Publishing Services,Tonbridge,Kent;form or by any means,without the prior permission in writing ofp163b:Russ Munn/Agstockusa/Science Photo Library:p165:Oxford University Press,or as expressly permitted by law,bySciencephotos/Alamy:p168:Shutterstock:p171:Andrewlicence or under terms agreed with the appropriate reprographicsLambert Photography/Science Photo Library:p190t:Molekuul.rights organization.Enquiries concerning reproduction outsideBeShutterstock;p198t:Martyn F.Chillmaid;p198b:Martyn F.the scope of the above should be sent to the Rights Department,Chillmaid/Science Photo Library:p202:Green Gate PublishingOxford University Press,at the address above.Services:p204:E.R.Degginger/Science Photo Library:p205t:You must not circulate this work in any other form and you mustKzenon/Shutterstock:p205b:Science Photo Library:p207:impose this same condition on any acquirerShutterstock;p212:Martyn F.Chillmaid/Science Photo Library:p223:Martyn F.Chillmaid;p230:Corel:p231:Martyn F.British Library Cataloguing in Publication DataChillmaid/Science Photo Library:p232:iStockphoto:p239:Data availableMartyn F.Chillmaid/Science Photo Library:p244:Andrew978-0-19-837602-6Lambert Photography/Science Photo Library:p245:AndrewLambert Photography/Science Photo Library:p249:Corel:p250:10987654321Colin Cuthbert/Newcastle University/Science Photo Library:p271:Shutterstock;p322:Colin Cuthbert/Science Photo Library:Paper used in the production of this book is a natural,recyclablep328:Public Health England/Science Photo Library;p353t-product made from wood grown in sustainable forests.p444:Shutterstock:p456:MeePoohyaPhoto/Shutterstock;p461:The manufacturing process conforms to the environmentalShutterstock:p465:dto3mbb/iStockphoto:p503:Shutterstock:regulations of the country of origin.p521:Science Photo Library.Printed in United KingdomAlthough we have made every effort to trace and contact allcopyright holders before publication this has not been possiblein all cases.If notified,the publisher will rectify any errors oromissions at the earliest opportunity.Links to third party websites are provided by Oxford in good faithand for information only.Oxford disclaims any responsibility forthe materials contained in any third party website referenced inthis work.AQA material is reproduced by permission of AQAWith special thanks to Colin Chambers for his advice andguidance,and Emma Gadsden for her editing and managementof the project.