structure and properties 0.0 / 5 ? ChemistryStructure and bondingGCSEAQA Created by: Amym0709Created on: 13-06-17 18:58 Why do ionic structures have high melting points? They have many strong electrostatic forces holding the ions together 1 of 21 What happens when the ionic compound has been melted? ions are free to move and allows them to carry electrical charge 2 of 21 What can split up the lattice? Water 3 of 21 why can ionic substances conduct electricity when molten or when dissolved in water? The ions are free to move and can carry the charge 4 of 21 Why does petrol not conduct electricity? the molecules in petrol have no overall charge 5 of 21 What is a giant covalent structure? A huge 3D network of covalent bonds 6 of 21 Describe a giant covalent structure? Every atom in the structure is joined by to several strong covalent bond. 7 of 21 Is the melting point of a giant covalent structure low or high and why? Very high because they have strong bonds 8 of 21 Give two examples of giant covalent structures? Diamond and graphite 9 of 21 What is diamond a form of? Carbon 10 of 21 How many carbon atoms are covalently bonded in diamond? 4 11 of 21 How many carbon atoms are covalently bonded in graphite? 3 12 of 21 Why is graphite slippery and grey? There are no covalent bonds between the layers and so they slide over each other 13 of 21 What are atoms in metal arranged like? In layers 14 of 21 Why are melts so easily shaped? The layers of atoms are arranged in layers so can slide over each other 15 of 21 What are alloys? Mixture of metals 16 of 21 Why are alloys stronger than a pure metal? The alloy has different sized atoms and aren't in layers so they can slide over each other therefore it is difficult for the layers to slide. 17 of 21 What are shape memory alloys? They can be bent into a different shape but when they are heated they go back tho their original shape 18 of 21 What is a thermosoftening polymer? It is made up of individual polymer chains that are tangled together. 19 of 21 What happens when a thermosoftening polymer is heated? it turns soft then hardens again 20 of 21 When heated what do therosetting polmers do? They do not melt or soften 21 of 21
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