in general, with increasing relative molecular mass 1.43 1.49 explain why substances with giant covalent structures are solids with high melting and boiling points 1.44 & 1.45: statements deleted New statement 1.50 explain how the structures of diamond, graphite and C60 fullerene influence physical properties, including electrical conductivity and hardness 1.49 1.51 know that covalent compounds do not usually conduct electricity (h) Metallic bonding New statement, on 1.46 1.52C know how to represent a metallic lattice by a 2-D diagram 1.46: becomes a bold statement 1.53C understand metallic bonding in terms of electrostatic attractions 1.47: becomes a bold statement 1.54C explain typical physical properties of metals, including electrical conductivity and malleability (i) Electrolysis 1.48: statement deleted 1.49: becomes a bold statement 1.55C understand why covalent compounds do not conduct electricity 1.50: becomes a bold statement 1.56C understand why compounds conduct electricity only when molten or in aqueous solution 1.51 1.52: statement deleted – New statement 1.57C know that anion and cation are terms used to refer to negative and positive ions respectively 1.53: becomes a bold statement 1.58C describe experiments to investigate electrolysis, using inert electrodes, of molten & 1.54 compounds (including lead(II) bromide) and aqueous solutions (including sodium chloride, dilute sulfuric acid and copper(II) sulfate) and to predict the products 1.55: becomes a bold statement 1.59C write ionic half-equations representing the reactions at the electrodes during electrolysis & 1.29: becomes a bold statement and understand why these reactions are classified as oxidation or reduction 1.54: becomes a practical 1.60C Practical: investigate the electrolysis of aqueous solutions statement 1.56 & 1.57: statements deleted
in general, with increasing relative molecular mass 1.49 explain why substances with giant covalent structures are solids with high melting and boiling points 1.43 1.44 & 1.45: statements deleted 1.50 explain how the structures of diamond, graphite and C60 fullerene influence physical properties, including electrical conductivity and hardness New statement 1.51 know that covalent compounds do not usually conduct electricity 1.49 (h) Metallic bonding 1.52C know how to represent a metallic lattice by a 2-D diagram New statement, on 1.46 1.53C understand metallic bonding in terms of electrostatic attractions 1.46: becomes a bold statement 1.54C explain typical physical properties of metals, including electrical conductivity and malleability 1.47: becomes a bold statement (i) Electrolysis 1.48: statement deleted 1.55C understand why covalent compounds do not conduct electricity 1.49: becomes a bold statement 1.56C understand why compounds conduct electricity only when molten or in aqueous solution 1.50: becomes a bold statement 1.51 – 1.52: statement deleted 1.57C know that anion and cation are terms used to refer to negative and positive ions respectively New statement 1.58C describe experiments to investigate electrolysis, using inert electrodes, of molten compounds (including lead(II) bromide) and aqueous solutions (including sodium chloride, dilute sulfuric acid and copper(II) sulfate) and to predict the products 1.53: becomes a bold statement & 1.54 1.59C write ionic half-equations representing the reactions at the electrodes during electrolysis and understand why these reactions are classified as oxidation or reduction 1.55: becomes a bold statement & 1.29: becomes a bold statement 1.60C Practical: investigate the electrolysis of aqueous solutions 1.54: becomes a practical statement 1.56 & 1.57: statements deleted
IGCSE-Chemistry-2017-mapping-document.docx