12   5 The question is about electronegativity and its influence on bonding. (a) State what is meant by the term electronegativity. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (b) Explain the trend in electronegativity for the Group 7 elements. 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(c) Describe what you understand by the term ‘continuum of bonding type’ in relation to electronegativities. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... Turn over 13   (d) The table gives data for chlorine and chlorine compounds of some Period 3 elements. The data show evidence that the type of bonding in compounds is a continuum across Period 3. Empirical formula Melting temperature / °C Electrical conductivity Sodium chloride NaCl 801 Yes, when molten Magnesium chloride MgCl2 714 Yes, when molten Aluminium chloride AlCl3 180 (sublimes) No Silicon tetrachloride SiCl4 –70 No Phosphorus(III) chloride PCl3 –112 No Chlorine Cl2 –102 No Discuss the extent to which the data in the table demonstrate a continuum of bonding type. Include reference to the data of three of the substances in the table with different types of bonding. 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(Total for Question 5 = 9 marks)