Lessons
Chemistry · 22 topics · 81 lessons
Model all matter as particles — classify substances as elements, compounds, or mixtures, explain the three states using kinetic molecular theory, and define temperature as average particle kinetic energy.
Go inside the atom — discover the three subatomic particles, master nuclide notation (Z and A), and understand how isotopes arise from different neutron counts.
Light from Atoms — The Evidence for Energy Levels
Continuous vs Line Spectra · The Hydrogen Emission Spectrum
Shells, Subshells, and How Electrons Fill Them
Shells and Subshells · Writing Electron Configurations
What Does an Orbital Look Like?HL
Orbital Shapes — s and p
Ionization Energy from Spectra and Successive IE (HL)HL
Convergence Limit and Ionization Energy · Successive Ionization Energies
Discover how the mole links the invisible world of atoms to measurable masses, enabling quantitative chemistry calculations including moles, molar mass, empirical formulas, concentration, and gas volumes.
Explore the three assumptions that underpin the ideal gas model, see how PV = nRT connects pressure, volume and temperature, and discover exactly when and why real gases deviate from ideal behaviour.
Explore how atoms become ions through electron transfer, deduce ion charges from the periodic table, and master the six key polyatomic ions. Foundation for understanding ionic bonding and lattice structures.
Explore how atoms share electrons to form covalent bonds, draw Lewis structures to represent molecules, and discover the special coordinate (dative) bond. Foundation for molecular geometry, polarity, and intermolecular forces.
How Atoms Share Electrons
What Is a Covalent Bond? · Lewis Structures · Coordinate (Dative) Bond
Shape, Polarity and Electronegativity
VSEPR Theory · Electronegativity and Bond Polarity · Molecular Polarity
From Molecules to Materials
Giant Covalent Structures · Intermolecular Forces · IMF, Physical Properties and Chromatography
HL: Resonance, Benzene, Expanded Octets and Formal Charge
Resonance Structures · Benzene and Delocalization · Expanded Octets · Formal Charge
Sigma and Pi Bonds, and Hybridization
Sigma and Pi Bonds · Hybridization
Explore metallic bonding through the electron sea model — understand why metals conduct, bend, and vary so dramatically in strength. From copper wire to tungsten filaments, one model explains it all.
Learn how the Van Arkel-Ketelaar bonding triangle unifies ionic, covalent and metallic bonding into a single continuum. Use electronegativity differences to classify any substance and predict its physical properties — from high-melting ionic lattices to conducting metals to molecular gases.
The Bonding Triangle — Classifying All Materials
The Bonding Triangle · Placing Compounds on the Triangle
Alloys — Engineering the Metal Lattice
Alloys — Why Mixed Metals Outperform Pure Ones
Polymers — Addition and Condensation Polymerisation
Polymers and Monomers · Addition Polymerisation · Condensation Polymerisation (HL)
Explore how the periodic table reflects electron configurations, explain trends in atomic radius, ionization energy and electronegativity, and at HL analyse transition metal properties and coloured complexes.
How Is the Periodic Table Organized?
Organization of the Periodic Table · Atomic Radius · Ionic Radius · Ionization Energy · Electronegativity
What Do Groups and Periods Tell You?
Period 3 Oxide Structure · Period 3 Oxide Acid-Base · Alkali Metal Trends · Halogen Trends
Metals, Non-metals, and Keeping Score
Metallic/Non-metallic Continuum · Oxidation State Rules · Identifying Redox
Why Transition Metals Break the Rules
IE Discontinuities · Transition Element Properties
The Colour of Chemistry
Variable Oxidation States · Coloured Complexes
Classify organic compounds by functional group, apply IUPAC naming, identify isomers, and use spectroscopic techniques (MS, IR, NMR) to determine molecular structure.
The Language of Organic Chemistry
Representing Organic Molecules · General Formulas · Functional Groups · How Groups Determine Properties
Why Longer Chains Boil Higher
Homologous Series · Boiling Point Trends · Branching and Boiling Point · Solubility and Polarity
Naming Molecules and Their Alter Egos
IUPAC Nomenclature · Multiple Groups and Branching · Structural Isomerism
Mirror Images and Locked Rotations
Stereoisomerism · Cis-Trans Isomerism · Optical Isomerism
Molecular Fingerprints
Mass Spectrometry · Common Fragments · IR Spectroscopy
Reading the Molecular Map
¹H NMR Chemical Environments · Spin-Spin Coupling · Multi-Technique Analysis
Understand energy changes in reactions, distinguish exothermic from endothermic processes, sketch enthalpy diagrams, and measure enthalpy changes using calorimetry.
Calculate enthalpy changes from bond enthalpies and Hess's law, define standard enthalpies of combustion and formation, and construct Born-Haber cycles for ionic compounds.
Compare complete and incomplete combustion, evaluate fossil fuels and biofuels as energy sources, and explain how hydrogen fuel cells convert chemical energy to electricity.
When Fuels Burn
Complete Combustion · Specific Energy & Density · Incomplete Combustion · Health & Environmental Risks
Old Carbon vs New Carbon
Fossil Fuels · Environmental Impact · Biofuels · Biofuels vs Fossil Fuels
The Fuel with No Carbon
How Fuel Cells Work · Advantages & Limitations
Define entropy and predict sign changes, calculate Gibbs energy to determine spontaneity, analyse the four ΔH/ΔS sign combinations, and connect ΔG° to the equilibrium constant.
Apply stoichiometry to calculate amounts of reactants and products, identify limiting reagents, calculate percentage yield, and evaluate atom economy for green chemistry.
The Recipe Book of Chemistry
Balanced Equations as Mole Recipes · Mass-Mole Conversions · Solution Stoichiometry · Gas Stoichiometry
When You Run Out of Ingredients
Limiting & Excess Reagents · Percentage Yield
How Green Is Your Reaction?
Atom Economy Calculation · Atom Economy & Sustainability
Define reaction rate and apply collision theory, explain how temperature, concentration, surface area and catalysts affect rate, and determine rate equations and activation energy using the Arrhenius equation.
What Makes Reactions Happen?
Rate of Reaction · Measuring Rate · Collision Theory · Collision Theory and Factors
Speeding Up and Slowing Down
Factors Affecting Rate · Maxwell-Boltzmann · Activation Energy · Energy Profiles
The Shortcut Molecule
Catalysts · Catalysts & Maxwell-Boltzmann
Inside the Reaction: Step by Step
Reaction Mechanisms · Rate-Determining Step · Multi-Step Energy Profiles · Molecularity
The Mathematics of Speed
Rate Equations · Reaction Order · Order from Data · Order from Graphs
Why Temperature Changes Everything
Rate Constant & Temperature · Arrhenius Equation · Ea from ln k vs 1/T · Arrhenius Factor A
Describe dynamic equilibrium, construct Kc expressions, apply Le Chatelier's principle, use ICE tables for equilibrium calculations, and connect Kc to Gibbs energy.
Define Brønsted-Lowry acids and bases, calculate pH, distinguish strong from weak, interpret titration curves, and at HL calculate Ka/Kb, predict salt pH, and design buffer solutions.
The Proton Donors and Acceptors
Brønsted-Lowry Theory · Conjugate Pairs · Amphiprotic Species
Measuring Acidity
The pH Scale · Kw · Strong & Weak Acids
When Acids Meet Bases
Neutralization · Titration Curves
Quantifying Weak Acids and Bases
pOH Scale · Ka and Kb · Ka × Kb = Kw
The pH of Every Salt
Salt pH Prediction · All Four pH Curves
Indicators and Buffers
Acid-Base Indicators · Indicator Selection · Buffer Solutions · Buffer pH
Define oxidation and reduction, construct half-equations, explain voltaic and electrolytic cells, and at HL calculate cell potentials, connect to Gibbs energy, and predict electrolysis products.
Electrons on the Move
Oxidation & Reduction · Oxidation States · Oxidizing & Reducing Agents · Half-Equations · Combining Half-Equations
Which Metal Wins?
Activity Series · Displacement Reactions · Metals with Acids
Batteries: Turning Chemistry into Electricity
Voltaic Cell Components · How Voltaic Cells Work · Anode/Cathode/Electron Flow · Primary Cells · Secondary Cells
Forcing Reactions Backwards
Electrolytic Cells · Voltaic vs Electrolytic
Redox Goes OrganicHL
Oxidation of Alcohols · Reduction of Carbonyls · Catalytic Hydrogenation
Measuring the Drive to ReactHL
Standard Hydrogen Electrode · Cell Potential E° · ΔG° = −nFE°
Industrial ElectrolysisHL
Electrolysis of Aqueous Solutions · Predicting Products · Electroplating
Define radicals and explain their reactivity, describe homolytic fission by UV light, and outline the free-radical substitution mechanism with initiation, propagation and termination steps.
Define nucleophiles and electrophiles, describe SN2 and electrophilic addition mechanisms, and at HL compare SN1/SN2, apply Markovnikov's rule, and explain electrophilic substitution of benzene.
Attack of the Lone Pair
Nucleophiles · Nucleophilic Substitution (SN2) · Heterolytic Fission
The Electron-Hungry Species
Electrophiles · Electrophilic Addition
Beyond Protons: The Lewis ModelHL
Lewis Acids & Bases · Coordination Bonds · TM Complexes
One Step or Two?HL
SN1 vs SN2 · Leaving Groups
Alkenes, Carbocations, and the Benzene RingHL
Addition Reactions · Carbocation Stability · Electrophilic Substitution of Benzene