| 1 |
Meet carbon |
15 min |
- What atoms are made of, and what makes an atom carbon
- How many bonds carbon makes, and why
- How the same carbon atoms make both diamond and graphite
- What "organic" means to a chemist
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| 2 |
Sharing is bonding |
15 min |
- What a covalent bond is
- The difference between single, double and triple bonds
- How to read and draw displayed formulas
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| 3 |
Molecules in 3D |
15 min |
- Ball-and-stick and space-filling models
- Why bonds spread out as far apart as they can
- The tetrahedron, flat triangle and straight line shapes
- How lone pairs bend water and ammonia
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| 4 |
Chains and names |
20 min |
- The first eight alkanes, and what -ane, -ene and -yne mean
- How to read skeletal formulas
- What isomers are
- How to name an alkane with one branch
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| 5 |
Functional groups |
20 min |
- What a functional group is
- Alcohols, carboxylic acids, aldehydes, ketones, amines and esters
- How one small group changes the way a molecule behaves
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| 6 |
Rings and benzene |
20 min |
- How a carbon chain closes into a ring with 2 fewer hydrogens
- Why cyclohexane's ring folds into a chair
- Benzene's flat ring and the six electrons it shares
- Where benzene rings turn up in flavours, medicines and dyes
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| 7 |
Mirror-image molecules |
15 min |
- What makes a molecule left- or right-handed
- How to spot a carbon with four different groups
- Why mirror-image molecules can smell and act differently
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| 8 |
How reactions happen |
20 min |
- What happens to bonds, atoms and energy in a reaction
- Burning, where fuel and oxygen make carbon dioxide and water
- Addition across a C=C double bond
- Condensation, where two molecules join and give off water
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| 9 |
Polymers |
20 min |
- What monomers and polymers are
- How ethene's double bond opens to make poly(ethene), and how to draw a repeat unit
- How nylon and polyesters are made by condensation
- Why long chains make strong, bendy materials
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| 10 |
Molecules of life |
20 min |
- Glucose, and how it joins into starch and cellulose
- Fats and oils as big esters, and why oils stay liquid
- Proteins, made of amino acids joined by peptide bonds
- How DNA's base pairs fit together and store instructions
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| 11 |
Uneven sharing |
15 min |
- Why some atoms pull harder on shared electrons than others
- What partial charges are, and how chemists mark them
- Why water is a polar molecule and carbon dioxide is not
- How a microwave oven heats food by turning water molecules
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| 12 |
Molecules that stick together |
20 min |
- The pulls between molecules, and how they set boiling points
- What a hydrogen bond is, and why water boils at 100 °C
- Why oil and water separate, and what dissolves in what
- Why ice floats, and how hydrogen bonds hold DNA's base pairs together
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| 13 |
Acids and bases |
20 min |
- What makes a molecule an acid or a base
- How the pH scale works
- Why baking soda fizzes in vinegar
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| 14 |
Soap and washing up |
15 min |
- How soap is made by splitting fats with a strong base
- Why a soap molecule has a water-loving end and an oil-loving end
- How soap molecules wrap up grease so water can wash it away
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| 15 |
Colour |
20 min |
- How a coloured molecule absorbs some colours of light and sends back the rest
- Why long runs of alternating double bonds give carrots and tomatoes their colour
- Which molecules colour leaves, berries and red cabbage
- How red cabbage juice changes colour with pH
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| 16 |
Speeding reactions up |
20 min |
- Why molecules must collide the right way round and hard enough to react
- The energy hill every reaction has to climb
- Why heat, crowding and fine powders speed reactions up
- How catalysts and enzymes lower the hill
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| 17 |
Oxidation |
20 min |
- What oxidation means for a carbon compound
- How ethanol turns into ethanal and then ethanoic acid
- Why a cut apple turns brown, and how lemon juice slows it
- Why oils go rancid, and how antioxidants protect them
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| 18 |
Fuels and energy |
20 min |
- How crude oil is separated by boiling point
- Why burning a fuel gives out energy, and why some fuels give out more per gram
- What an octane rating measures
- Where biofuels such as ethanol and biodiesel come from
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| 19 |
Medicines |
20 min |
- How a medicine fits a pocket in its target protein
- How aspirin came from willow bark, and how it blocks an enzyme
- Why the hand of a medicine molecule matters
- How penicillin's squeezed ring jams the enzyme that builds a bacterium's wall
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| 20 |
Kitchen chemistry |
20 min |
- What happens when sugar turns to caramel
- Why toast and seared meat turn brown and taste richer
- Why an egg sets when you cook it
- How the ideas from the whole course meet in the kitchen
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| 21 |
Curly arrows |
20 min |
- What a curly arrow shows, from its tail to its head
- Why electrons flow from electron-rich places to electron-poor ones
- How a base takes H⁺ from an acid, in two arrows
- How bromine adds to ethene, step by step
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| 22 |
Separating mixtures |
20 min |
- How chemists tell a pure substance from a mixture
- How distillation separates liquids by boiling point
- How chromatography separates molecules by how they stick
- How decaf coffee is made
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| 23 |
How chemists see molecules |
20 min |
- Why each kind of bond absorbs its own infrared light
- How to spot O–H and C=O bonds in an infrared spectrum
- How a mass spectrometer weighs a molecule and its pieces
- What NMR shows about a molecule's hydrogens, and how MRI uses it
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| 24 |
Making molecules |
20 min |
- How chemists plan a synthesis by working backwards from the target
- How aspirin is made from salicylic acid in a lab
- How chemists check that a product is pure
- How to work out a yield, and why it falls with every step
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| 25 |
Greener chemistry |
20 min |
- What makes a chemical process greener, and how to work out its atom economy
- How plastics are recycled, and what the codes mean
- Why some plastics break down and others last
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| 26 |
Cis and trans |
15 min |
- Why groups cannot turn around a double bond
- The difference between cis and trans
- How light flips a molecule in your eye
- What trans fats are, and why they are solid
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| 27 |
Smell and taste |
20 min |
- How smell receptors turn molecules into patterns your brain reads
- Why some mirror-image pairs smell different and others smell the same
- Why chilli feels hot and menthol feels cold
- What the five tastes pick up, and why sweeteners are needed in such small amounts
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| 28 |
Messengers in your body |
20 min |
- What hormones and neurotransmitters are, and how they fit their receptors
- How your body builds dopamine and serotonin from amino acids
- Why your body makes just one hand of adrenaline
- How caffeine keeps you awake
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| 29 |
Air and climate |
25 min |
- What air is made of
- How some gases trap heat, and why nitrogen and oxygen let it pass
- Where the carbon dioxide and methane in the air come from
- How CFCs thinned the ozone layer, and how it is recovering
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| 30 |
New forms of carbon |
15 min |
- What graphene is, and why it is so strong and conducts electricity
- How nanotubes and buckyballs are rolled and folded graphene
- Where these new forms of carbon are used
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| 31 |
Rubber and stretch |
20 min |
- Why rubber's long cis chains coil, stretch and snap back
- How sulfur bridges between chains make rubber tough
- Why a stretched rubber band warms up
- What goes into tyres and synthetic rubber
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| 32 |
Glues |
15 min |
- How glue holds on to a surface
- Why superglue sets in seconds
- How two-part epoxy glue hardens
- Glues made by living things
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| 34 |
Sunscreen and skin |
15 min |
- What ultraviolet light is, and how it harms the DNA in skin
- How sunscreen molecules absorb UV and turn it into heat
- How melanin shades your skin cells
- How sunlight helps your skin make vitamin D
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| 35 |
Molecules that glow |
15 min |
- How a reaction can give out light
- How fireflies glow
- Why highlighter ink glows under ultraviolet light
- How organic LEDs light up a screen
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| 36 |
Photosynthesis |
20 min |
- What goes into photosynthesis and what comes out
- How chlorophyll catches light
- Where the oxygen you breathe comes from
- How an enzyme builds carbon dioxide into sugar
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| 39 |
Carbon in space |
20 min |
- How stars make carbon from helium and spread it through space
- How radio telescopes find molecules between the stars
- What meteorites, asteroids and comets carry
- Where buckyballs have turned up in space
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| 40 |
Why carbon? |
20 min |
- What makes carbon's chains and rings so stable
- How silicon, carbon's neighbour, compares
- Why carbon dioxide is a gas and silica is sand
- What silicon builds: glass, chips and silicones
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