Chemistry Unit 1 (2016-2022) (no longer current)
How can the diversity of materials be explained?
The development and use of materials for specific purposes is an important human endeavour. In this unit students investigate the chemical properties of a range of materials from metals and salts to polymers and nanomaterials. Using their knowledge of elements and atomic structure students explore and explain the relationships between properties, structure and bonding forces within and between particles that vary in size from the visible, through nanoparticles, to molecules and atoms. Students examine the modification of metals, assess the factors that affect the formation of ionic crystals and investigate a range of non-metallic substances from molecules to polymers and giant lattices and relate their structures to specific applications. Students are introduced to quantitative concepts in chemistry including the mole concept. They apply their knowledge to determine the relative masses of elements and the composition of substances. Throughout the unit students use chemistry terminology including symbols, formulas, chemical nomenclature and equations to represent and explain observations and data from experiments, and to discuss chemical phenomena. A research investigation is undertaken in Area of Study 3 related to one of ten options that draw upon and extend the content from Area of Study 1 and/or Area of Study 2.
AREA OF STUDY 1
Topics and Lessons
(activities listed in no particular order)
|Elements and the periodic table
• the relative and absolute sizes of particles that are visible and invisible to the unaided eye: small and giant molecules and lattices; atoms and sub-atomic particles; nanoparticles and nanostructures
• the definition of an element with reference to atomic number; mass number; isotopic forms of an element using appropriate notation
• spectral evidence for the Bohr model and for its refinement as the Schrödinger model; electronic configurations of elements 1 to 36 using the Schrödinger model of the atom, including s, p, d and f notations (with copper and chromium exceptions)
• the periodic table as an organisational tool to identify patterns and trends in, and relationships between, the structures (including electronic configurations and atomic radii) and properties (including electronegativity, first ionisation energy, metallic/non-metallic character and reactivity) of elements.
Introduce the concept of core charge before discussing trends in the periodic table.
• the common properties of metals (lustre, malleability, ductility, heat and electrical conductivity) with reference
to the nature of metallic bonding and the structure of metallic crystals, including limitations of representations;
general differences between properties of main group and transition group metals
• experimental determination of the relative reactivity of metals with water, acids and oxygen
• the extraction of a selected metal from its ore/s including relevant environmental, economic and social issues
associated with its extraction and use
• experimental modification of a selected metal related to the use of coatings or heat treatment or alloy production
• properties and uses of metallic nanomaterials and their different nanoforms including comparison with the properties of their corresponding bulk materials.
Demonstration of an alloy.
Students may like a more visual approach to deriving ionic formulae.
|Quantifying atoms and compounds
• the relative isotopic masses of elements and their representation on the relative mass scale using the carbon-12 isotope as the standard; reason for the selection of carbon-12 as the standard
• determination of the relative atomic mass of an element using mass spectrometry (details of instrument not required)
• the mole concept; Avogadro constant; determination of the number of moles of atoms in a sample of known mass; calculation of the molar mass of ionic compounds
• experimental determination of the empirical formula of an ionic compound.
|Area of Study 2
How can the versatility of non-metals be explained?
In this area of study students explore a wide range of substances and materials made from non-metals including molecular substances, covalent lattices, carbon nanomaterials, organic compounds and polymers. Students investigate the relationship between the electronic configurations of non-metallic atoms and the resultant structures and properties of a range of molecular substances and covalent lattices. They compare how the structures of these non-metallic substances are represented and analyse the limitations of these representations. Students study a variety of organic compounds and how they are grouped into distinct chemical families. They apply rules of systematic nomenclature to each of these chemical families. Students investigate useful materials that are made from non-metals, and relate their properties and uses to their structures. They explore the modification of polymers and the use of carbon-based nanoparticles for specific applications. Students apply quantitative concepts to molecular compounds, including mole concept and percentage composition by mass, and determine the empirical and molecular formulas of given compounds.
On completion of this unit the student should be able to investigate and explain the properties of carbon lattices and molecular substances with reference to their structures and bonding, use systematic nomenclature to name organic compounds, and explain how polymers can be designed for a purpose.
Materials from molecules
Predicting the shape of a molecule given its formula.
Carbon lattices and carbon nanomaterials
• the origin of crude oil and its use as a source of hydrocarbon raw materials
• the grouping of hydrocarbon compounds into families (alkanes, alkenes, alkynes, alcohols, carboxylic acids and non-branched esters) based upon similarities in their physical and chemical properties including general formulas, their representations (structural formulas, condensed formulas, Lewis structures), naming according to IUPAC systematic nomenclature (limited to non-cyclic compounds up to C10, and structural isomers up to C7) and uses based upon properties
• determination of empirical and molecular formulas of organic compounds from percentage composition by mass and molar mass.
• the formation of polymers from monomers including addition polymerisation of alkenes
• the distinction between linear (thermoplastic) and cross-linked (thermosetting) polymers with reference to structure, bonding and properties including capacity to be recycled
• the features of linear polymers designed for a particular purpose including the selection of a suitable monomer (structure and properties), chain length, degree of branching, percentage crystalline areas and addition of plasticisers
• the advantages and disadvantages of the use of polymer materials.
|Making of thermosetting plastic.
|Area of Study 3
Knowledge of the origin, structure and properties of matter has built up over time through scientific and technological research, including medical research, space research and research into alternative energy resources. As a result, patterns and relationships in structures and properties of substances have been identified, applied and modified, and a vast range of useful materials and chemicals has been produced. This research and development is ongoing and new discoveries are being made at an accelerating rate. In this area of study students apply and extend their knowledge and skills developed in Area of Study 1 and/or Area of Study 2 to investigate a selected question related to materials. They apply critical and creative thinking skills, science inquiry skills and communication skills to conduct and present the findings of an independent investigation into one aspect of the discoveries and research that have underpinned the development, use and modification of useful materials or chemicals. Students undertake a research investigation relevant to one of the following ten options. A question from the list under each option may be selected or students may develop their own research question relevant to Area of Study 1 and/or Area of Study 2 in conjunction with their teacher. For the selected question, students outline, analyse and evaluate relevant evidence to support their conclusions.
Option 1: The origin of the elements
Option 2: The development of the periodic table
Option 3: The lanthanoids and actinoids
Option 4: Using light to solve chemical puzzles
Option 5: Glass
Option 6: Crude oil
Option 7: Surfactants
Option 8: Polymers and composite materials
Option 9: Nanomaterials
Option 10: The life cycle of a selected material or chemical