Unit 1: Chemical fundamentals (structure, properties and reactions)
8 dot points across 3 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.
Topic 1: Properties and structure of atoms
A focused answer to the QCE Chemistry Unit 1 dot point on atomic structure. Defines protons, neutrons and electrons in the nuclear model, walks through nuclear notation and isotopes, and shows the weighted-mean calculation of relative atomic mass from mass spectrometry abundances.
A focused answer to the QCE Chemistry Unit 1 dot point on electron configuration and periodic trends. Walks through the s, p and d subshell filling order using the aufbau principle, Pauli exclusion and Hund's rule, then explains atomic radius, first ionisation energy and electronegativity in terms of effective nuclear charge and shielding.
Topic 2: Properties and structure of materials
A focused answer to the QCE Chemistry Unit 1 dot point on covalent bonding. Walks through drawing Lewis structures for molecules and polyatomic ions, predicts shapes (linear, bent, trigonal planar, trigonal pyramidal, tetrahedral) using VSEPR theory, and determines bond and overall molecular polarity from electronegativity differences and the symmetry of the structure.
A focused answer to the QCE Chemistry Unit 1 dot point on intermolecular forces. Distinguishes dispersion forces, dipole-dipole attractions, and hydrogen bonding by origin and relative strength, then uses them to explain melting and boiling points, solubility, viscosity and surface tension of covalent molecular substances.
A focused answer to the QCE Chemistry Unit 1 dot point on ionic bonding. Explains how electron transfer forms cations and anions held in a 3D lattice by electrostatic attraction, predicts formulae for binary ionic compounds, and links lattice structure to the high melting point, brittleness, conductivity only when molten or dissolved, and variable solubility of ionic substances.
A focused answer to the QCE Chemistry Unit 1 dot point on metallic bonding. Describes the cation-and-delocalised-electron model, then explains the characteristic properties of metals (electrical and thermal conductivity, malleability, ductility, lustre, variable melting point) in terms of mobile electrons and the way the lattice deforms under stress.
Topic 3: Chemical reactions (reactants, products and energy change)
A focused answer to the QCE Chemistry Unit 1 dot point on energy in chemical reactions. Distinguishes exothermic (negative Delta H) and endothermic (positive Delta H) reactions, draws energy profile diagrams with activation energy, and uses calorimetry data with q = mcDeltaT to calculate molar enthalpy of reaction.
A focused answer to the QCE Chemistry Unit 1 dot point on the mole concept. Converts between mass, moles, particles, gas volumes (at STP and SLC) and solution concentration; uses balanced-equation stoichiometric ratios to determine limiting reagent, theoretical yield and percentage yield.