About the Author

David Ballard is a former Head of Chemistry with many years' experience of teaching in secondary and further education in England. He is an experienced examiner and teacher, and is currently Chief Examiner for A Level Chemistry for a leading awarding body. // Rhodri Thomas is currently a Deputy Head with many years' experience of teaching Chemistry in schools and universities in the UK and overseas. He is an experienced examiner and is currently a Principal Examiner for A Level Chemistry for a major awarding body.