A student says, "Elements always become more reactive going down a group in the Periodic Table."
Which observation shows that the student is wrong?
Chlorine displaces bromine from potassium bromide solution.
Potassium reacts more vigorously with water than sodium does.
Barium reacts more vigorously with water than calcium does.
Iodine is a solid at room temperature, but chlorine is a gas.
60 exam-style questions on OCR GCSE Chemistry 4.1 Predicting chemical reactions, covering 4.1.1 Properties and trends in Groups 1, 7 and 0, 4.1.2 Properties of the transition metals, 4.1.3 Reactivity predicted from position in the Periodic Table, and 4.1.4 Reactivity of metals and the reactivity series. Each one has a worked solution and a mark scheme showing where the marks go.