Combined Science (A) J250,04 Foundation November 2020, OCR GCSE Past Papers with Mark Schemes

The document is a GCSE (9–1) Combined Science (Chemistry) A past paper. It covers essential chemistry topics, including reaction mechanisms (displacement, oxidation, cracking), periodic trends (Group 1 and Group 7 elements), and environmental science (greenhouse gases, water purification). It also assesses practical skills, such as experimental design and interpretation of results, with emphasis on industrial processes (fractional distillation, electrolysis) and material properties. Questions demand understanding of energy transfer, rates of reaction, and the reactivity series, providing a comprehensive test of applied chemistry knowledge.