In your own words, define the term ‘delocalised electrons’ in metals and comment on why these are important when understanding the high melting temperatures of metals. (Advisory word count: 100 words) (5 marks) Video 1 An iron nail immersed in a copper sulfate solution (this video contains no audio) b. Now answer the following questions: i. How does the reactivity series shown in Topic 5: Part 2, Figure 2.5 (repeated below as Figure 1) help you understand the displacement reaction taking place in Video 1? What can be observed on the surface of the iron nail? (Advisory word count: 100 words) (4 marks) Topic 5: Part 2, Section 2.5.1 ‘Displacement reactions’ Topic 5: Part 2, Section 2.6 ‘Oxidation and reduction’ Topic 4: Part 3, Section 3.7.1 ‘Maths skill: Quantifying amounts and concentrations of solutions’ Topic 5: Part 1, Section 1.2 ‘Arrangement of atoms in metals’ Topic 5: Part 2, Section 2.5 ‘Reactivity series’ Advice on answering Question 1 This question relates to: Q