Practise Edexcel IGCSE Chemistry Group 1 (alkali metals) – lithium, sodium and potassium with exam-style questions for IGCSE Chemistry. 21 questions, matched to the Edexcel IGCSE Chemistry (4CH1) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.