Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Alkali Metals
85 practice questions
Topics covered
Practice questions
1–10 of 14 · Hard
Question 1
2 marks · Hard
Answer and see the solution →State two observations you would expect when a piece of sodium is added to water. Explain how these observations differ from the reaction of potassium with water.
Question 2
5 marks · Hard
Answer and see the solution →The table below shows some properties of Group 1 metals at room temperature.
Metal Melting Point (°C) Lithium 181 Sodium 98 Potassium 64 Rubidium 39 Caesium 29 (a)[1 mark]Describe the trend in melting point as you go down Group 1 from lithium to caesium.
(b)[1 mark]Predict the appearance (physical state and colour) of caesium at room temperature.
(c)[3 marks]Explain, in terms of atomic structure, the trend in reactivity from lithium to caesium.
Question 3
2 marks · Hard
Answer and see the solution →Describe the appearance of lithium and potassium at room temperature. State one difference you would notice between them by observation.
Question 4
2 marks · Hard
Answer and see the solution →Explain, in terms of their electronic configurations, why a rubidium atom loses its outer electron more easily than a sodium atom.
Question 5
5 marks · Hard
Answer and see the solution →(a)[1 mark]State the electronic configuration of a potassium atom.
(b)[2 marks]Using the electronic configurations, compare the positions of the outer electrons in sodium and potassium atoms.
(c)[2 marks]Explain, with reference to their atomic structure, why potassium reacts more vigorously with water than sodium does.
Question 6
2 marks · Hard
Answer and see the solution →Why is the outer electron in a caesium atom less strongly attracted to the nucleus than in a lithium atom? Give two reasons.
Question 7
2 marks · Hard
Answer and see the solution →Describe what you would observe if a freshly cut piece of potassium is left exposed to air. Explain why this observation occurs.
Question 8
5 marks · Hard
Answer and see the solution →The table lists several Group 1 metal compounds:
(a)[3 marks]Compound Colour Solubility in water Lithium nitrate ? ? Sodium sulfate ? ? Potassium carbonate ? ? Complete the table by stating the usual colour and solubility in water of each compound.
(b)[2 marks]Explain why most compounds of lithium, sodium, and potassium dissolve to form colourless solutions.
Question 9
2 marks · Hard
Answer and see the solution →Explain why alkali metals must be stored under oil, using what happens when they are left uncovered in air.
Question 10
2 marks · Hard
Answer and see the solution →State and explain one reason why francium is predicted to be more reactive than potassium.