1. 1
   A technician compares samples of iron (a transition metal) and sodium (a Group 1 metal) of equal size, measuring density, hardness and melting point for each sample.

   (a)

   A technician measures the density of a sample of iron and a sample of sodium of equal size. Which metal is expected to have the higher density?

   [1 mark]

   • AIron
   • BSodium
   • CBoth have identical density
   • DNeither has a measurable density

   (b)

   The technician then tries to scratch each sample with a knife. Which metal is expected to be softer and easier to cut?

   [1 mark]

   • ANeither can be cut
   • BIron
   • CBoth are equally soft
   • DSodium

   (c)

   Give two further ways, besides density and hardness, in which iron (a transition metal) differs from sodium (a Group 1 metal) in its physical or chemical properties.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A student adds a small piece of potassium to a trough of water, observing a vigorous reaction, and then repeats the experiment using a small piece of copper of a similar size.

   (a)

   A small piece of potassium (Group 1) is added to water and reacts vigorously, while a small piece of copper (a transition metal) is added to water separately. What is observed for the copper?

   [1 mark]

   • AIt dissolves completely, forming a coloured solution
   • BIt reacts as vigorously as the potassium
   • CNo visible reaction occurs
   • DIt produces hydrogen gas rapidly

   (b)

   Which of these correctly explains the difference in reactivity observed between potassium and copper?

   [1 mark]

   • ACopper is more reactive than potassium
   • BTransition metals such as copper are much less reactive than Group 1 metals such as potassium
   • CBoth metals are equally reactive with water
   • DPotassium does not react with water at all

   (c)

   Explain, in terms of reactivity, why the student observed such a different result when copper was added to water compared with potassium.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   An engineer is selecting materials for the load-bearing steel beams of a new building and considers whether a transition metal such as iron, or a Group 1 metal such as sodium, would be more suitable, comparing their densities, melting points, strength and reactivity.

   (a)

   An engineer is choosing a metal to construct load-bearing beams for a building. Explain why a transition metal such as iron, rather than a Group 1 metal such as sodium, would be chosen for this purpose.

   [3 marks]

   (b)

   The engineer also considers density and melting point data for both metals. Describe how the density and melting point of transition metals typically compare with those of Group 1 metals, and explain why this makes transition metals more suitable for construction.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A materials scientist is writing a report comparing the transition metals (such as iron and copper) with the Group 1 metals (such as sodium and potassium) to explain why the two groups have such different roles in industry and everyday life.

   (a)

   Compare, in detail, the physical and chemical properties of transition metals with those of Group 1 metals, and explain how these differences determine the everyday and industrial uses of each group.

   [6 marks]

   (b)

   Explain why mercury, a transition metal, is an exception to the general trend that transition metals have higher melting points than Group 1 metals, and discuss what this tells us about using general trends to predict the properties of individual elements.

   [6 marks]

   Total for question 4: 12 marks

End of questions