IGCSE Chemistry (Edexcel Certificate) Revision Guide This Revision Guide covers the Edexcel Level 1/Level 2 Certificate in Chemistry and the Edexcel International GCSE in Chemistry. It contains concise study notes for every topic, supported by clear diagrams and helpful tips for doing well in the Paper 1 and Paper 2 exams (material that's only needed for Paper 2 is clearly marked). A section of detailed advice on Experimental Techniques is also included.