Bonding is best described as a continuum between the ionic, covalent and metallic models, and can be represented by a bonding triangle.
Use bonding models to explain the properties of a material.
A triangular bonding diagram is provided in the data booklet.
The position of a compound in the bonding triangle is determined by the relative contributions of the three bonding types to the overall bond.
Determine the position of a compound in the bonding triangle from electronegativity data.
Predict the properties of a compound based on its position in the bonding triangle.
To illustrate the relationship between bonding type and properties, include example materials of varying percentage bonding character. Only binary compounds need to be considered.
Calculations of percentage ionic character are not required.
Electronegativity data are given in the data booklet.
Alloys are mixtures of a metal and other metals or non-metals. They have enhanced properties.
Explain the properties of alloys in terms of non-directional bonding.
Illustrate with common examples such as bronze, brass and stainless steel. Specific examples of alloys do not have to be learned.
Polymers are large molecules, or macromolecules, made from repeating subunits called monomers.
Describe the common properties of plastics in terms of their structure.
Examples of natural and synthetic polymers shouldbe discussed.
Addition polymers form by the breaking of a double bond in each monomer.
Represent the repeating unit of an addition polymer from given monomer structures.
Examples should include polymerization reactions of alkenes.
Structures of monomers do not have to be learned but will be provided or will need to be deduced from the polymer.
Condensation polymers form by the reaction between functional groups in each monomer with the release of a small molecule.
Represent the repeating unit of polyamides and polyesters from given monomer structures.
All biological macromolecules form by condensation reactions and break down by hydrolysis.