IGCSE Chemistry 0620 lectures
55 short lectures, one for each part of the syllabus, in the order it is taught. Each one teaches a topic on the board in a few minutes. The teaching part is free to watch; a free account opens the rest of every lecture: worked examples, practice questions and real past-paper questions answered.
Chapter 1 States of matter
Chapter 2 Atoms, elements and compounds
- Atoms: protons, neutrons and electronsEvery substance you have ever touched is built from atoms, and every atom is built from just three kinds of particle.6 min
- Isotopes and relative atomic massLook at the mass of chlorine in the Periodic Table.7 min
- Electronic configurationSodium is soft and explosive in water.5 min
- Ionic bondingSodium is a soft metal that fizzes violently in water.6 min
- Covalent bonding and simple moleculesWater, oxygen, carbon dioxide and methane are all made of small molecules.6 min
- Giant covalent structuresA diamond is the hardest natural material, and it is clear and it does not conduct.6 min
- Metallic bondingA copper wire carries electricity into your home, and can be bent round a corner without snapping.6 min
- Comparing structures and propertiesA scientist is given an unknown white solid.7 min
Chapter 3 Stoichiometry
- Relative formula massA chemist cannot count atoms, but she can add up their masses on paper.6 min
- Formulae of ionic compoundsSodium chloride is NaCl, but magnesium chloride is MgCl₂.6 min
- Writing and balancing equationsBurn a candle, and the wax seems to disappear.7 min
- Ionic equationsMix a clear solution of silver nitrate with a clear solution of sodium chloride, and a white solid appears at once.7 min
- The mole and the Avogadro constantA single drop of water contains billions upon billions of molecules.6 min
- Moles: amount, mass and molar massIn the lab you cannot count particles, but you can weigh a substance on a balance.6 min
- Reacting massesA factory wants to make a tonne of a product.7 min
- Gas volumes at r.t.p.Weighing a solid is easy.7 min
- Concentration and titration calculationsTwo glasses of orange squash can look the same size, but one tastes much stronger.9 min
- Percentage composition by massA farmer has two bags of fertiliser, and both contain nitrogen.6 min
- Empirical and molecular formulaeEthene is C₂H₄, and propene is C₃H₆.7 min
- Water of crystallisationBlue copper sulfate crystals look dry, but heat them and steam rises, and they turn into a white powder.7 min
Chapter 4 Electrochemistry
- Principles of electrolysis and molten compoundsAluminium foil, chlorine for swimming pools and the coating on a gold watch all have something in common.7 min
- Predicting products and half-equationsIn a molten compound there are only two kinds of ion, so the products are easy.7 min
- Electrolysis of brine and copper(II) sulfateSeawater is a cheap, endless supply of salt.6 min
- Electroplating and fuel cellsA silver spoon that is really steel, and a car that runs on hydrogen with only water coming out of the exhaust.7 min
Chapter 5 Chemical energetics
Chapter 6 Chemical reactions
- Collision theory and rate graphsIron rusts over years.6 min
- Dynamic equilibrium, position of equilibrium and industryHeat blue copper sulfate crystals and they turn white, giving off water.6 min
- Oxidation numbers and redoxRust forming on a nail, a candle burning, a battery powering your phone.6 min
- Oxidising and reducing agentsIn every redox reaction one substance is oxidised and another is reduced.6 min
Chapter 7 Acids, bases and salts
- Properties of acids and bases, proton transferLemon juice tastes sour.5 min
- The pH scale, indicators, strong and weak acidsHydrochloric acid and vinegar are both acids.6 min
- Neutralisation and oxidesA bee sting is acidic.6 min
- Making soluble and insoluble salts, hydrated saltsBeautiful blue crystals of copper sulfate can be grown on a school bench, from black copper oxide powder and clear acid.6 min
Chapter 8 The Periodic Table
- The Periodic Table and trends across a periodMore than a hundred elements, and you do not have to learn them one by one.6 min
- Group I metalsMost metals are hard.6 min
- Halogens and displacement reactionsChlorine is a pale green gas.6 min
- Noble gases and transition elementsHelium in a party balloon never reacts with anything.6 min
Chapter 9 Metals
- The reactivity seriesA gold ring buried for a thousand years still shines.5 min
- Displacement reactions and extractionDrop a clean iron nail into blue copper sulfate solution, and in minutes it grows a pink-brown coat.5 min
- Extracting iron and aluminiumYour bicycle, your fridge and your car all contain iron or aluminium.6 min
- Alloys and rust protectionPure iron is soft and rusts.5 min
Chapter 10 Chemistry of the environment
- Clean air and photosynthesisTake a deep breath.6 min
- Air pollutants, catalytic converters and global warmingBehind every car, bus and power station is a plume that you cannot always see.5 min
- Water tests and domestic water treatmentThe water that comes out of your tap was once a river or a reservoir, with mud, leaves and microbes in it.5 min
Chapter 11 Organic chemistry
- Homologous series, naming and saturationCarbon makes millions of compounds, from petrol to plastics to perfume.5 min
- Petroleum and crackingCrude oil comes out of the ground as a thick black liquid.5 min
- Reactions of alkanes and alkenesEthane and ethene are both hydrocarbons with two carbons.5 min
- Addition polymersEthene is a gas.6 min
- Ethanol: manufacture, combustion and oxidationIn Brazil many cars run on ethanol made from sugar cane.6 min
- Esters, condensation polymers and proteinsThe smell of pineapple, the fabric of a fleece jacket, and the muscle in your arm.6 min
Chapter 12 Experimental techniques
Also for IGCSE Chemistry 0620
Which topics come up most in IGCSE Chemistry 0620 past papers, counted from every paper since 2004.