GCSE

• 3 types of chemical bonds

  ionic, covalent, metallic
• The reaction of metal with oxygen can be represented by the general word equation Metal + Oxygen -> Metal oxide.
• Metals that lose their outer shell electrons most easily are more reactive.
• The reaction of metal with acid can be represented by the general word equation Metal + Acid -> Salt + Hydrogen.
• The hydrogen gas test involves igniting the gas with a lit splint and observing a squeaky pop.
• The reactions of metals with acid can be compared by measuring the temperature change during the reaction.
• An ore is a metal combined with other elements found in rock.
• Reduction is the loss of oxygen.
• elements below carbon are extracted by reduction
• Electrolysis is used for elements above carbon in the reactivity series
• An ionic equation is a balanced equation that omits spectator ions.
• Electrolysis is the process of breaking down a compound using electrical energy.
• A spectator ion is an ion that does not change in a reaction.
• In terms of oxidation and reduction, OILRIG stands for Oxidation Is Loss Reduction Is Gain.
• The disadvantage of electrolysis is that it requires a large amount of electrical energy and is expensive.
• Ionic bonding is electrostatic attraction between oppositely charged ions.
• Covalent bonding is electrostatic attraction between a positive nucleus and a shared pair of negative electrons.
• Metallic bonding is electrostatic attraction between positively charged ions and delocalised electrons.
• Non-metals form ionic bonds with metals.
• Non-metals form covalent bonds with non-metals.
• In ionic bonding, metals lose their outer shell electrons to have a full shell and form a positively charged ion.
• In ionic bonding, non-metals gain outer shell electrons to fill their shell and become negatively charged ions.
• Atoms become ions to attain a full outer electron shell.
• The bonding in Graphite is characterised by each carbon being strongly, covalently bonded to 3 others and having one delocalised electron, forming hexagonal layers with weak intermolecular forces.
• Ionic materials do not conduct electricity because the ions are not able to move and carry the charge throughout the structure.
• The bonding in an ionic material is characterised by strong electrostatic attraction between oppositely charge ions in all directions.
• Graphene is expected to have high strength and conduct electricity.
• The bonding in a simple, covalent material is characterised by weak intermolecular forces that require little energy to break and strong covalent bonds that don't break easily.
• The melting points of ionic materials are high.
• Graphite and graphene are two of the giant covalent materials that conduct electricity.
• The structure of an ionic compound is a giant ionic lattice.
• An individual particle does not have a melting point because it will not have the same properties as the bulk material and no bonds.
• The strength of a weak intermolecular force increases as molecules become larger.
• Graphite conducts electricity because it has delocalised electrons, while a molten ionic compound has ions that can move.
• Small molecules do not conduct electricity because there are no delocalised electrons or ions that can move and carry the charge throughout the structure.
• The bonding in Diamond is characterised by each carbon being strongly, covalently bonded to 4 others.
• The melting point and boiling point are points at which a solid melts or a gas condenses.
• The limitations of the particle model are that all particles are represented as spheres and that the spheres are solid.
• % yield = actual yield/ theoretical yield x 100
• atom ecomony = Mr of desired products / Mr of all reactants