During a teacher demonstration, a small piece of potassium is added to room-temperature water. Which set of observations is expected?
It floats, fizzes steadily and moves slowly across the surface.
It sinks, fizzes and makes the water turn cloudy.
It melts, moves rapidly and ignites with a lilac flame.
It melts into a ball, fizzes and darts across the surface.
86 exam-style questions on AQA GCSE Chemistry 4.1 Reactivity of metals, covering 4.1.1 Metal oxides, 4.1.2 The reactivity series, 4.1.3 Extraction of metals and reduction, and 4.1.4 Oxidation and reduction in terms of electrons. Each one has a worked solution and a mark scheme showing where the marks go.