Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Alkali Metals
85 practice questions
Topics covered
Practice questions
81–85 of 85
Question 81
6 marks · Normal
Answer and see the solution →Rubidium and caesium are Group 1 alkali metals.
(a)[2 marks]State two physical properties that rubidium and caesium have in common with other Group 1 metals.
(b)[2 marks]Describe what you would observe if a small piece of caesium was dropped into water.
(c)[2 marks]Explain, in terms of electronic configuration, why caesium reacts more rapidly with water than sodium.
Question 82
6 marks · Normal
Answer and see the solution →The alkali metals show clear trends down Group 1.
(a)[2 marks]Rubidium and caesium are both placed below potassium in Group 1 of the Periodic Table. Predict how the reactivity of caesium compares to that of rubidium and explain your answer.
(b)[1 mark]Describe how the size of alkali metal atoms changes as you move from lithium to caesium in Group 1.
(c)[2 marks]Explain, in terms of electronic configuration, why alkali metals become more reactive as you move down Group 1.
(d)[1 mark]State the charge on an ion formed when a caesium atom reacts.
Question 83
6 marks · Normal
Answer and see the solution →Rubidium (Rb) and caesium (Cs) are Group 1 alkali metals. Their physical and chemical properties follow group trends seen in other Group 1 metals such as lithium, sodium and potassium.
(a)[2 marks]State two physical properties that rubidium and caesium have in common with lithium, sodium, and potassium.
(b)[1 mark]Rubidium and caesium both react vigorously with water.
Write a balanced chemical equation for the reaction of caesium with water.
(c)[2 marks]Describe what you would observe when a small piece of caesium is added to water. Give two observations.
(d)[1 mark]Explain, in terms of electronic structure, why caesium reacts more violently with water than potassium.
Question 84
7 marks · Hard
Answer and see the solution →This question is about the reactions of rubidium and caesium with water and the reactions of Group 1 metals with air.
(a)[3 marks]Describe what you would observe when a small piece of caesium is added to water. Explain your answer in terms of the position of caesium in Group 1.
(b)[2 marks]Sodium reacts with oxygen in the air to form a white solid of sodium oxide. Write a balanced chemical equation for this reaction, including state symbols.
(c)[2 marks]Caesium oxide is also a white solid. Predict its formula and give a reason for your answer.
Question 85
4 marks · Hard
Answer and see the solution →A student investigates Group 1 (alkali) metals and their compounds.
(a)Rubidium and caesium are placed below potassium in Group 1 of the Periodic Table. Predict and explain how the reaction of caesium with water is expected to be different from lithium, sodium, and potassium.
(b)[2 marks]The student has solid samples of lithium, sodium, and potassium. She cuts a fresh surface and leaves each in air. State what she would observe for each metal after a few minutes. Explain the reason for any differences in what she sees.
(c)[2 marks]Group 1 metal ions form colourless compounds unless the other ion is coloured. The student prepares potassium sulfate crystals and notices that the crystals are white and dissolve easily in water. Give two reasons, based on the properties of Group 1 metal compounds, to explain these observations.