Scheme of work Chemistry - Bonding, structure, and the properties of matter This resource provides guidance for teaching the Bonding, structure and the properties of matter topic from our new GCSE Chemistry (8462). It has been updated from the draft version to reflect the changes made in the accredited specification. The scheme of work is designed to be a flexible medium term plan for teaching content and development of the skills that will be assessed. It is provided in Word format to help you create your own teaching plan – you can edit and customise it according to your needs. This scheme of work is not exhaustive; it only suggests activities and resources you could find useful in your teaching. 4.2 Bonding, structure and the properties of matter 4.2.1 Chemical bonds, ionic, covalent and metallic Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing Opportunities to develop Scientific Communication skills Opportunities to develop and apply practical and enquiry skills Self/peer assessment opportunities and resources Reference to past questions that indicate success 4.2.1.1 There are three types of strong chemical bonds: ionic, covalent and metallic. For ionic bonding the particles are oppositely charged ions. For covalent bonding the particles are atoms which share Students should be able to explain chemical bonding in terms of electrostatic forces and the transfer or sharing of electrons. 1 Define ‘electrostatic forces of attraction’. Extended writing: describe why atoms bond in order to obtain a noble gas configuration/full outer level of electrons. Demo the formation of sodium chloride in a fume cupboard.
pairs of electrons. For metallic bonding the particles are atoms which share delocalised electrons. Ionic bonding occurs in compounds formed from metals combined with non-metals. Covalent bonding occurs in non-metallic elements and in compounds of Metallic bonding occurs in metallic elements and alloys. Describe/draw the structure of common atoms and suggest how they could bond to obtain a full outer level of electrons. 4.2.1.2 When a metal atom reacts with a non-metal atom, electrons in the outer shell of the metal atom are transferred. Metal atoms lose electrons to become positively charged ions. Non-metal atoms gain electrons to become negatively charged ions. The ions produced by metals in Groups 1 and 2 and by in Groups 6 and 7 have the electronic Students should be able to: draw dot and cross diagrams for ionic compounds formed by metals in Groups 1 and 2 with non-metals in Groups 6 and 7 work out the charge on the ions of metals and non-metals from the group number of the element, limited to the metals in Groups 1 and 2, and non-metals in Groups 6 and 7. 0.5 Tabulate common atoms and state the charges of the ions formed. Grade 9: explain an example of ionic bonding including detail on electron transfer, group numbers of the atoms involved and the use of correct terms, eg cation and anion. Use magnesium ribbon to produce magnesium oxide. Draw the dot and cross diagram for this reaction. Video clips: YouTube: YouTube:
three dimensional diagrams to represent a giant ionic structure work out the empirical formula of an compound from a given model or diagram that shows the ions in the structure. WS 1.2 Students should be able to visualise and represent 2D and 3D forms including two dimensional representations of 3D objects. MS 4a, 1a, 1c. 4.2.1.4 When atoms share pairs of electrons, they form covalent bonds. These bonds between atoms are strong. Covalently bonded substances may consist of small molecules. Some covalently bonded substances have very molecules, such as polymers. Some covalently bonded substances have giant covalent structures, such as Students should be able to: recognise substances as small molecules, polymers or giant structures from diagrams showing their bonding recognise common substances that consist of small molecules from their chemical formula. draw dot and diagrams for the molecules of hydrogen, chlorine, oxygen, nitrogen, hydrogen 1 Extended writing: describe the difference between simple covalent substances and giant covalent substances. Grade 9: explain an example of covalent bonding including detail on electron transfer, group numbers of the atoms involved and the use of correct terminology. Demo the formation of hydrogen chloride. Draw the dot and cross diagram for this reaction. Model simple covalent substance using molecular model kits. Demo giant covalent structures using molecular model kits. Video clip:
4.2.1.5 Metals consist of giant structures of atoms arranged in a regular pattern. The electrons in the outer shell of metal atoms are delocalised and so are free to move through the whole structure. The sharing of delocalised electrons gives rise to strong metallic bonds. The bonding in metals may be represented in the following form: WS 1.2 Students should be able to: recognise substances as metallic structures from diagrams showing their bonding visualise and represent 2D and 3D forms including two dimensional representations of 3D objects. MS 5b 0.5 Define ‘delocalised electrons’. Use copper wire and silver nitrate solution to grow silver crystals. clips: YouTube: 4.2.2 How bonding and structure are related to the properties of substances Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to develop and apply practical and enquiry skills Self/peer assessment opportunities and resources Reference to past questions that indicate success 4.2.2.1 The three states of matter are solid, liquid and gas. Melting and freezing take Students should be able to: 1 Extended writing: describe the properties of Video clips:
forces, that all particles are represented as spheres and that the spheres are solid. 4.2.2.2 In chemical equations, the three states of matter are shown as (s), (l) and (g), with (aq) for aqueous solutions. Include appropriate state symbols in chemical equations for the reactions in this specification. 0.5 Describe balanced symbol equations including the states of matter. 4.2.2.3 Ionic compounds have regular structures (giant ionic lattices) in which there are strong electrostatic forces of attraction in all directions between oppositely charged ions. These compounds have high melting points and high boiling points because of the large amounts of energy needed to break the many strong bonds. When melted or dissolved in water, ionic compounds conduct electricity because the ions are free to move and so charge can flow. Knowledge of the structures of specific ionic compounds other than sodium chloride is not required. 1 Extended writing: describe the electrical conductivity of ionic substances. Extended writing: explain why solid ionic substances do not conduct electricity but dissolved or molten ionic substances do conduct electricity. Grade 9: explain how ionic substances dissolve in water. Extended writing: explain why sodium chloride is difficult to melt. Research some uses of ionic substances. Extension: make links between the uses of ionic substances, their properties and structure. Practically test the conductivity of ionic compounds, eg sodium chloride and potassium chloride. Video clip YouTube: 4.2.2.4 Substances that consist of molecules are usually gases or liquids that have relatively low melting points and boiling points. Students should be able to use the idea that intermolecular forces are weak compared with covalent to explain 0.5 Extended writing: describe melting points and boiling points of covalent substances. Research some uses of covalent substances. Extension: make links between the uses of Video clip YouTube:
These substances have only weak forces between the molecules (intermolecular forces). It is these intermolecular forces that are overcome, not the covalent bonds, when the substance melts or boils. The intermolecular forces increase with the size of the molecules, so larger molecules have higher melting and boiling points. These substances do not conduct electricity because the molecules do not have an overall electric charge. the bulk properties of molecular substances. Extended writing: explain why the melting point and boiling point increases as the size of the molecule does in terms of intermolecular forces. Extended writing: explain why covalent substances do not conduct electricity. Grade 9: explain why pure water does not conduct electricity but tap water does conduct electricity. covalent substances, their properties and structure. Practically test the conductivity of simple covalent substances using ethanol and solid wax pieces. 4.2.2.5 Polymers have very large molecules. The atoms in the polymer molecules are linked to other atoms by strong covalent bonds. The intermolecular forces between polymer molecules are relatively strong and so these substances are solids at room temperature. Students should be able to recognise polymers from diagrams showing their bonding. 1 Extended writing: explain how ethene polymerises. Model polymers. Make a polymer from cornstarch. Investigate the properties of plastic bags. clips: YouTube: 4.2.2.6 Substances that consist of giant covalent structures are solids with very high melting points. All of the atoms in these structures Students should be able to recognise giant covalent structures from diagrams showing their bonding and structure. 0.5 Extended writing: describe the structure of diamond, silicon dioxide and graphite. Research some uses of covalent substances. Extension: make links between the uses of
are linked to other atoms by strong covalent bonds. These bonds must be overcome to melt or boil these substances. Diamond and graphite (forms of carbon) and silicon dioxide (silica) are examples of giant covalent structures. WS 1.2 MS 5b Extended writing: explain how covalent substances boil. covalent substances, their properties and structure. 4.2.2.7 Metals have giant structures of atoms with strong metallic bonding. This means that most metals have high melting and boiling points. In pure metals, atoms are arranged in layers, which allows metals to be bent and shaped. Pure metals are too soft for many uses and so are mixed with other metals to make alloys which are harder.. Explain why alloys are harder than pure metals in terms of distortion of the layers of atoms in the structure of a pure metal. WS 1.2 1 Extended writing: describe melting points and boiling points of metallic substances. Extended writing: explain why the melting point and boiling point of metallic substances are high. Extended writing: describe the structure of metal alloys. Research some uses of metallic substances. Extension: make between the uses of metal substances, their properties and structure. Research some uses of metal alloys. Extension: make between the uses of metal alloys, their properties and structure. Video clips: 4.2.2.8 Metals are good conductors of electricity because the delocalised electrons in the metal carry electrical charge through the metal. Metals are good conductors of thermal energy because energy is 0.5 Extended writing: explain why metallic substances conduct electricity.
transferred by the delocalised electrons. 4.2.3 Structure and bonding of carbon Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to develop and apply practical and enquiry skills Self/peer assessment opportunities and resources Reference to past questions that indicate success 4.2.3.1 In diamond, each carbon atom forms four covalent bonds with other carbon atoms in a giant covalent structure, so diamond is very hard, has a very high melting point and does not conduct electricity. Explain the properties of diamond in terms of its structure and bonding. WS 1.2 Visualise and represent 2D and 3D including two dimensional representations of 3D objects. MS 5b 1 Extended writing: link the properties of diamond to the structure. Research the properties of diamond. Model the structure of diamond using model kits. clips: YouTube: 4.2.3.2 In graphite, each carbon atom forms three covalent bonds with three other carbon atoms, forming layers of hexagonal rings which have no covalent bonds between the layers. In graphite, one electron from each carbon atom is delocalised. Explain the properties of graphite in terms of its structure and bonding. Know that graphite is similar to metals in that it has delocalised electrons. WS 1.2 0.5 Extended writing: link the properties of graphite to the structure. Extended writing: explain why graphite conducts electricity. Research the properties of graphite. Model the structure of graphite using model kits. Video clip: