1. The vat. Sulfur at 200 °C. Can the tap still run?
Estimate: is 200 between 115 and 445, or past a stall?
Answer
Yes. Melted, not yet gas. It pours. If you treated 200 as “hot so it must be gas,” you skipped the boiling stall near 445 °C.
Chemistry / Why ice holds
Uncut
Stuff · Lesson 1 · form costs heat
Why ice holds
You can stand on a lake in January. The same water would swallow you in June. Nothing new was mixed in. The stuff did not change. The hold between the bits did. Changing form (aggregationsform: fast, flytande, gasform) costs heat — or gives heat back.
— writing a move, physics side.
Origins
Craft,
always
always
People melted metal, boiled water, watched frost, and dried food in the cold long before anyone drew a particle. The kitchen and the foundry already knew form can change while the stuff stays the stuff.
Black
1760s
1760s
Joseph Black weighed ice and water and tracked heat that went in while the thermometer stalled. That plateau is the tool. He called the hidden bill latent heat — heat spent on a new form, not a hotter reading.
19th century
The kinetic picture — bits jiggling, hold loosening — arrives after the measurement. Useful cartoon. Not how the stall was first caught.
Iodine, frost,
name later
name later
Violet crystals going to gas with no puddle, frost on grass with no rain: known as curiosities. School later names the skip sublimation. The puzzle is the missing liquid, not the Latin.
Honesty: this page is a kitchen and a thermometer, not a plant tour. We are not copying anyone’s foundry photo.
Feed it heat. Watch the thermometer stall.
This is the floor of the lesson — the plateau is the point, the way the rectangle was the point of times. Drag energy in. The pot is the same stuff the whole way.
Kitchen proof later. First: see the stall with your own hand on the slider.
Heat in · thermometer −20 °C · all ice
Stall — heat in, T still
Black track: thermometer against heat in. Flat means heat is paying for a new form, not a hotter reading.
Smältpunkt: the stall while ice is still there. Kokpunkt: the stall while water is still there. Energin går åt att bryta hållet — inte att höja temperaturen.
The lake holds because the bits still hold
In the hard form the bits are locked in place. You stand on that lock. Feed the ice heat at 0 °C and the thermometer does not climb yet: the heat is buying a slide, not a hotter ice. When enough of the lock is paid for, you fall in.
“Bits held together” is a later cartoon. People used ice and melt for millennia without drawing particles. The measurement came first.
The kettle does not eat the water
The water in a kettle does not disappear. Hold something cold over it — a spoon, a lid — and the drops come back (kondenserar).
A wet road in April can dry with no bubbles and no scream. That is leaving as gas from the surface, below the stall (avdunstar — not kokning). The kettle at the stall makes bubbles through the whole pot (kokning vid kokpunkten). Same destination. Different job.
Frost with no rain — and the dry freezer
Grass can go white on a clear night with no shower. The air’s water can skip the puddle and land as ice (sublimerar: gas → fast).
Leave bread in a freezer too long and it tastes dry. Ice left the food as gas — again no puddle in the bag (fast → gas). School later names both skips sublimation. The puzzle is the missing liquid, not the Latin.
Pour it, then let it keep the shape
Casting is older than chemistry class. You melt a metal, pour it, and wait. It keeps the mold’s shape because it gives heat out as it goes hard (stelning). Heat in to melt. Heat out to set. Same stuff, new permission to flow — then the permission is taken back.
Any foundry, any century. We are not copying a plant, a bar weight, or a photo from a book.
A glacier can sit near 0 °C for centuries
Extra heat does not make a hotter glacier. It pays for melt. The ice can stay at the stall while the mountain loses mass. That is the same plateau you dragged on the slider, stretched across a valley.
is taken in to melt or to boil. Heat is given out when the stuff goes hard or when gas becomes liquid. The thermometer can sit still while that bill is paid.
(smältning och ångbildning tar energi; stelning och kondensation ger energi)
The puzzle that made the tool
People melted fat, boiled water, watched frost, and cast metal for millennia. The honest origin of “heat can go in without the thermometer moving” is a measurement, not a cartoon of bits.
Joseph Black, in the 1760s, weighed ice and water and tracked the heat that vanished from the thermometer’s story while the ice was still there. He called that hidden bill latent heat — heat that is in the change of form. Particle pictures of vibrating bits are a later model. Useful. Not how the stall was first caught.
Honesty: Black did not have our school diagram. We use the stall you just dragged because it is the same fact, drawn. We do not pretend 19th-century kinetic theory solved his ice bath.
A cut question, then a job
Ange svavels aggregationsform vid 200 °C.
Nothing is at stake. Nobody is pouring, storing, or standing on anything.
A sulfur vat sits at 200 °C. Can you still pour it, or has it gone hard — or left as gas?
Typical public values, not a copied school table: sulfur melts near 115 °C and boils near 445 °C (around ordinary air pressure, 101 kPa). At 200 °C it still pours (flytande form).
Jobs — typical numbers, then a decision
These melting and boiling points are round public figures at about 101 kPa. Treat them as typical, not as a book’s table.
| Stuff | Typically melts | Typically boils |
|---|---|---|
| Oxygen | −218 °C | −183 °C |
| Nitrogen | −210 °C | −196 °C |
| Water | 0 °C | 100 °C |
| Sulfur | 115 °C | 445 °C |
| Table salt | 801 °C | 1465 °C |
| Iron | 1538 °C | 2862 °C |
Smältpunkt / kokpunkt. Fast — flytande — gasform. Siffrorna är typiska publika värden, inte en avskriven tabell.
2. The cylinder. Laboratory oxygen is brought toward −200 °C. Is it still a gas you cannot pour, or has it started to sit as a liquid?
Estimate: −200 compared with −183 (boil) and −218 (melt).
Answer
At −200 °C oxygen is below its typical boiling point and above its typical melting point — it pours. Cool it past about −218 °C and it goes hard. Warm it past about −183 °C and you are back to gas.
3. The brick. Molten table salt is poured at 1300 °C. Will it be a brick in a room at 20 °C?
Estimate: 20 against 801.
Answer
Yes. 20 °C is far below the typical melt. It gives heat out and goes hard (stelning). 1300 °C is still below the typical boil, so you were pouring a liquid, not a gas, and the room takes it to a solid.
4. The stalls, named as jobs. At about what temperature does sulfur’s gas become pourable again? When does nitrogen stop being a pour and become a brick? When does iron go hard from the melt?
Those are the boiling stall run backwards, and the melting stalls.
Answer
Sulfur gas condenses near 445 °C. Nitrogen goes hard near −210 °C. Iron goes hard near 1538 °C — a typical public figure, not a copied cell, and not a one-degree quarrel with anyone’s textbook.
Gate — four, all required
Each right gate item is 20 points. Hands-on is 20. Wrong is 0 until you retry and get it. Next unlocks only at 100 — and only if that page exists.
1. Heat can go in while the thermometer sits still. What is the heat doing?
2. A wet road dries in April. A kettle screams at the stall. Same skip, or not?
3. Frost on grass, no rain. Must the water have been a puddle first?
4. A worksheet says “ange aggregationsformen.” Which is the real job?