When a small piece of potassium is added to a trough of cold water, a vigorous reaction occurs, producing a lilac flame and an alkaline solution.
State the chemical formulae of the two products of this reaction.
75 exam-style questions on Edexcel GCSE Chemistry 7.1 Group 1, covering 7.1.1 Classifying elements by group in the periodic table and 7.1.2 Properties and reactions of the alkali metals. Each one has a worked solution and a mark scheme showing where the marks go.