Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Predicting the properties of francium
19 practice questions
Practice questions
11–19 of 19
Question 11
3 marks · Normal
Answer and see the solution →The melting point of alkali metals decreases as you move down the group:
Melting points of Group 1 elements Element Atomic number Melting point / °C Lithium 3 181 Sodium 11 98 Potassium 19 64 Rubidium 37 39 Caesium 55 29 Francium 87 ? Use the trend shown in the table to estimate a value for the melting point of francium.
Question 12
3 marks · Normal
Answer and see the solution →Explain why francium compounds are expected to be colourless and soluble in water.
Question 13
4 marks · Normal
Answer and see the solution →The graph below shows the melting points of some alkali metals against their atomic numbers.
Melting points of alkali metals (a)[1 mark]Describe the trend shown by the graph.
(b)[1 mark]Estimate the melting point of francium (atomic number 87) using the graph.
(c)[2 marks]Explain how you used the data to make your estimate.
Question 14
1 mark · Normal
Answer and check →Which statement best predicts what would happen if a small piece of francium was exposed to air at room temperature?
- A.It would remain shiny and not react.
- B.It would tarnish almost instantly.
- C.It would slowly change colour over several days.
- D.It would melt and form a green compound.
Question 15
2 marks · Normal
Answer and see the solution →Give the formula and name for the hydroxide formed when francium reacts with water.
Question 16
4 marks · Normal
Answer and see the solution →Answer the following questions about francium and its properties.
(a)[2 marks]Explain why we can predict the properties of francium, even though it is extremely rare.
(b)[2 marks]State one property francium would have as a solid and one as an aqueous compound.
Question 17
2 marks · Hard
Answer and see the solution →State and explain one reason why francium is predicted to be more reactive than potassium.
Question 18
5 marks · Hard
Answer and see the solution →Francium is a Group 1 alkali metal that has never been seen directly. Chemists use trends to predict its properties.
(a)[1 mark]State the expected physical appearance of francium when freshly cut.
(b)[2 marks]Explain why francium would be stored under oil if it could be collected in the laboratory.
(c)[2 marks]Describe and explain what you would expect to happen if francium was dropped into water.
Question 19
2 marks · Hard
Answer and see the solution →Predict whether francium would form coloured or colourless compounds in water, and explain your answer.