Arrange the Group I elements caesium, lithium, potassium, rubidium and sodium in order of reactivity with water, starting with the most reactive.
Name the alkaline solution produced when caesium reacts with cold water.
Describe one further difference between the physical properties of Group I elements and transition elements.
Predict astatine's physical state at room temperature and pressure.
Describe how the colour of the solution changes. State the starting colour of the potassium bromide solution and the final colour of the reaction mixture.
Identify the species that is oxidised. Explain your reasoning.
Calculate the overall energy change for the reaction using bond energies. Follow these steps: • Calculate the total amount of energy needed to break the bonds in 1 mole of $\text{Br}_2(g)$ and 1 mole of $\text{Cl}_2(g)$. • Calculate the total amount of energy released when the bonds in 2 moles of $\text{BrCl}(g)$ are formed. • Calculate the overall energy change for the reaction.