Tag
Mixing & changing
Dissolving, rusting, rising, and turning into something else — 48 tiny stories across 5 shelves.
What things are made of
Atoms, metal, glass, plastic, and every kind of stuff — 27 stories.
All what things are made of →Sour, and eager to give something away
What Makes Something an Acid?
An alkali soaks those particles up instead, so the two cancel to salty water and heat — and your stomach survives its own acid on renewed slime.
Let’s go →Wrong-sized atoms get in the way
Why Is Pure Gold Too Soft for a Ring?
A pure metal bends because its atoms slide in neat rows. Mix in a differently sized atom and the rows jam, which is why alloys beat what went into them.
Let’s go →Pieces too small to see
What Is Everything Made Of?
Everything around you is built from about a hundred kinds of atom, so small that a sheet of paper is half a million of them thick.
Let’s go →Where roast smells come from
Why Does Food Turn Brown When It Cooks?
Above about 140 degrees, sugars and proteins start reacting with each other and build hundreds of colour and flavour molecules that were not there before.
Let’s go →Shaking a mixture until it gives up
How Does Cream Turn Into Butter?
Cream is fat droplets floating in water, each in a protective coat. Churning smashes those coats off so the fat clumps and the watery part drains away.
Let’s go →Splitting a liquid into two
How Does Milk Become Cheese?
Cheese-making starts by splitting milk into solid curds and watery whey, throwing most of the whey away, then pressing, salting and ageing what is left.
Let’s go →It sets by reacting, not by drying
Why Does Concrete Go Hard Under Water?
Concrete does not dry out. The cement reacts with water and grows interlocking crystals, which is why it sets at the bottom of a river.
Let’s go →A narrow window of heat
Why Does Custard Suddenly Scramble?
Egg proteins unfold and tangle to thicken a custard over a few degrees, then clump and squeeze the liquid out over the next few. The margin is very thin.
Let’s go →Making a colour hold on
How Does Colour Stay in Cloth?
Getting colour onto cloth is easy; surviving twenty washes is the hard part, so a dye bonds to the fibres rather than sitting on the surface.
Let’s go →Flow into every crevice, then stop flowing
How Does Glue Hold Two Things Together?
Two flat-looking surfaces touch at only a few high points, so glue has to be runny enough to flood every tiny pit, and then stop being runny.
Let’s go →A candle, a mouse, and a jar
How We Found Out What Air Is
Sealing a candle and a mouse under a jar showed that air is a mixture, and that only one part of it keeps a flame or an animal alive.
Let’s go →A mesh built from fruit
Why Does Jam Set?
Long pectin chains from the fruit link into an invisible mesh once acid and sugar allow it, and the sugary liquid is held still inside it.
Let’s go →It was never dissolved
Why Does Juice Separate in the Glass?
Juice is not one liquid. The cloudiness is solid fruit floating rather than dissolved, and floating things get sorted by weight once the glass goes still.
Let’s go →Melted, then cooled too fast to crystallise
How Do You Turn Sand Into a Window?
Glass is melted sand cooled so fast that its atoms freeze in a jumble, never getting the chance to line up into the crystals they would prefer.
Let’s go →Mostly a surface job
What Does a Marinade Actually Do?
A marinade barely gets in. Salt travels, acid tenderises the surface and then toughens it, and oil carries the flavours that water cannot dissolve.
Let’s go →Mixed together, not joined together
Why Can You Get the Salt Back Out?
Stir iron filings into sand and a magnet lifts them straight back out. Air, milk, soil and steel are all mixtures; genuinely pure things are rare.
Let’s go →Two things make a third thing
What Happens When Atoms Join Up?
An explosive gas and the gas fires need combine to make water, which puts fires out. Atoms joined up behave nothing like the atoms that went in.
Let’s go →A thread made from nothing that grew
Why Was Nylon Invented?
Nylon was the first useful fibre that came from neither plant nor animal: long molecule chains pulled straight, endless and rot-proof.
Let’s go →Three jobs in one tin
What Is Paint Made Of?
Every paint is the same three things: coloured powder, a glue to hold it on the wall, and a liquid that thins it and then leaves once it dries.
Let’s go →Making the jar uninhabitable
Why Does Pickling Stop Food Rotting?
Microbes need water and a comfortable acidity to spoil food. A pickle jar removes both at once, then seals the lid so no new ones can get in.
Let’s go →Millions of small links, joined into chains
What Is Plastic Actually Made Of?
Heating lets the chains slide without breaking, so plastic can be moulded again — but different chains refuse to mix, which is why sorting matters.
Let’s go →Melting versus mashing
Why Does Glass Recycle Better Than Paper?
Melting rebuilds glass and metal exactly, but tearing paper apart shortens its fibres a little each time, so paper eventually runs out of lives.
Let’s go →Fat, turned inside out
How Is Soap Made?
Soap is made by cooking fat with something strongly alkaline until every molecule has a grease-gripping tail and a water-gripping head.
Let’s go →Turning tough into silky
Why Do Cooks Boil Bones for Hours?
Hours of gentle heat unwind the toughest tissue in an animal into gelatine, which is what gives stock its body. A hard boil only makes it cloudy.
Let’s go →Scrubbing, and rebuilding
What Is Toothpaste Actually Doing?
Most of the cleaning is the brush. The paste is mild grit, detergent and flavour, plus the fluoride that actually rebuilds the enamel.
Let’s go →Nothing alive has the tool for it
Why Does Plastic Never Rot?
Life evolved keys for wood, leaf, bone and fat over a very long time. A bacterium that can slowly eat PET turned up beside a Japanese plant in 2016.
Let’s go →Bacteria doing the thickening
How Does Milk Become Yoghurt?
Bacteria eat the sugar in milk and make acid, and the acid makes the milk proteins link up into the soft set. Nothing is added but the bacteria and time.
Let’s go →Everyday wonders
Kitchen, bubbles, echoes, and odd little magic — 16 stories.
All everyday wonders →Fruit rusting
Why Does a Cut Apple Turn Brown?
Cutting an apple lets an enzyme that was safely stored meet the oxygen in the air, and together they build a brown pigment over the exposed surface.
Let’s go →A gas being made
Why Does Baking Soda Fizz?
Baking soda meets an acid and the two swap parts to make carbon dioxide. The fizz is a brand-new gas taking up far more room than the ingredients did.
Let’s go →A fungus breathing out
Why Does Bread Rise?
Yeast is alive: it eats the sugar in the dough and breathes out carbon dioxide, and a stretchy gluten net catches the gas instead of letting it escape.
Let’s go →Atoms joining a queue
How Do Crystals Grow?
Atoms can only attach in certain positions, so a repeating pattern inside shows up as flat faces outside. Salt makes cubes because it stacks in cubes.
Let’s go →Broken up, not vanished
Where Does Sugar Go in Water?
The sugar is all still there — the water weighs exactly that much more. It disappears because a single molecule is smaller than a wavelength of light.
Let’s go →Smell molecules escaping
Why Does a Fridge Smell of Everything at Once?
Every food quietly gives off molecules, and a sealed cold box gives them nowhere to go. Fatty foods then soak them up and hold on to them.
Let’s go →Lowering the freezing point
Why Does Salt Melt Ice?
Salt does not warm anything. It gets in the way of water molecules rejoining the ice, so the freezing point drops and ice below zero turns to liquid.
Let’s go →Every mix absorbs more
Why Does Mixing Paint Make Brown?
Every paint absorbs some of the light landing on it, so mixing paints absorbs more and more until almost nothing bounces back. Mixing light is the reverse.
Let’s go →A liquid that panics
Why Can You Run on Cornflour and Water?
Shove the grains together faster than the water between them can escape and they jam like a solid. Stop pushing and the mixture is a liquid again.
Let’s go →Cloudy water is useful water
Why Do Cooks Save the Pasta Water?
The cloudiness is starch, and starch does three jobs at once: it thickens the sauce, holds oil and water together, and makes the whole thing cling.
Let’s go →Iron combining with oxygen
Why Does Metal Go Rusty?
Rust is iron chemically joining with oxygen and water to become something new and crumbly, and it flakes off to expose fresh metal underneath.
Let’s go →A molecule with two ends
How Does Soap Clean?
One end of a soap molecule grips grease and the other grips water, so grease is wrapped in a water-friendly ball and simply rinses off instead of clinging.
Let’s go →Gas hiding in plain sight
Where Do the Bubbles in Fizzy Drinks Come From?
The gas was dissolved into the liquid under pressure. Opening the bottle releases it, and the surplus gathers on rough spots and rises as bubbles.
Let’s go →How tightly the molecules hold
Why Are Some Things Solid and Others Runny?
Solid, liquid and gas are the same molecules with the same attractions — what changes is whether heat energy or that attraction is currently winning.
Let’s go →Sugars and proteins reacting
Why Does Toast Go Brown?
Toast is not just drying out. Heat drives sugars and proteins to react into new brown, aromatic compounds — the same reaction as searing a steak.
Let’s go →Proteins forced to unfold
How Does Egg White Turn Into Foam?
Whisking unfolds the proteins in egg white so they wrap every air bubble in a strong film. Beat too long and those proteins clump and the foam collapses.
Let’s go →Life & body
Seeds, hearts, senses, and growing things — 3 stories.
All life & body →Throw it all out, take back what you need
What Do Kidneys Actually Do?
Kidneys do not pick the rubbish out of your blood. They dump nearly everything small, then deliberately reclaim the water, salt and sugar.
Let’s go →The chemistry room
What Is a Liver For?
Take two-thirds of a liver away and the rest grows back within a couple of months. No other large organ in you will do anything of the kind.
Let’s go →Too much, in the wrong place
What Makes Something Pollution?
Nothing is pollution by itself. It becomes pollution when more of it arrives somewhere than that place can break down or carry away.
Let’s go →Animals
Creatures on land, in the sea, and in the air — 1 story.
All animals →How things work
Everyday machines, taken apart — 1 story.
All how things work →