Melting, freezing and boiling
Tests: 8 of 11 right · Exam: 2 of 4 right · Kind: ★★ · Understood: 7 of 15 · Run: 2026-10-18, commit f3c23ea72
Lesson 24 of the physics course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: the lesson in the corpora.
Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: the lesson's questions in the corpora.
Test 1 · ★★ · wrong ✗
me mate says the can's leaking cos it's wet outside. right?
- 1. No, it is sweat from his hand — ← Mova's choice · no support
- 2. No, the water came from the air and condensed on the cold can — ✓ the right answer · no support
- 3. Yes, the drink seeps through the metal — no support
- 4. Yes, cans always leak when cold — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 2 · ★★ · right ✓
Ugh, left the door of the fridge open to cool the kitchen on a hot day. Will that work?
- 1. No, the fridge just moves heat round the kitchen and adds its own — ← Mova's choice · ✓ the right answer · no support
- 2. No, fridges only work at night — no support
- 3. Yes, if you leave it open all night — no support
- 4. Yes, it will cool the whole house — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 3 · ★★ · right ✓
What would happen if a bridge were built with no gaps at all?
- 1. It would be stronger in every way, with no weak points — no support
- 2. It could crack or buckle as it grows in summer — ← Mova's choice · ✓ the right answer · score 5
- 3. Nothing at all would happen — no support
- 4. It would shrink away to nothing — no support
Why: It took the question to ask what happens next. It chose option 2 with score 5, the only option with support. Its support: lesson 24, line 14: «Bridges grow a little in summer and shrink in winter, and the gaps with metal teeth stop them cracking or buckling.», reached through the same lesson line as the sentence the question matched. What matched: the same action «grow» (+2); the same doer «bridges» (+2); the same property (+1). · the question and its options parsed, with trees and pragmatics
Test 4 · ★★ · wrong ✗
A drink with ice and a drink of cold water start at the same temperature. Which stays cold longer?
- 1. Neither, both warm up instantly to room temperature — ← Mova's choice · no support
- 2. The one with ice, because melting soaks up heat — ✓ the right answer · no support
- 3. Both exactly the same — no support
- 4. The cold water one — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 5 · ★★ · right ✓
In a cartoon a snowman melts in seconds when the Sun comes out. What is closer to the truth?
- 1. Snow melts the instant sunlight touches it — score 1
- 2. Snow never melts in sunshine — score 4
- 3. Snow melts only at night — score 1
- 4. Snow melts slowly, because it reflects sunlight and melting needs lots of heat — ← Mova's choice · ✓ the right answer · score 6
Why: It took the question to ask which statement is true. It chose option 4 with score 6, against 4 for the next best. Its support: lesson 24, line 16: «Snow does not melt the moment the Sun comes out, because white snow bounces most sunlight away and melting needs a lot of heat.», reached through the same lesson line as the sentence the question matched. What matched: the same action «need» (+2); the same doer «melting» (+2); the same thing acted on «lot» (+2). · the question and its options parsed, with trees and pragmatics
Test 6 · ★★ · wrong ✗
Why does your breath make a little cloud on a cold day but not on a warm one?
- 1. The cold air turns the vapour in your breath into droplets — ✓ the right answer · no support
- 2. Your lungs only make little clouds in winter, to keep you warm — ← Mova's choice · score 7
- 3. Your breath is hotter in winter — score 3
- 4. Your breath is smokier in winter — score 3
Why: It took the question to ask why something happens (its cause). It chose option 2 with score 7, against 3 for the next best. Its support: lesson 24, line 9: «Windows steam up on a cold morning because warm, damp air inside condenses on the cold glass, the same way your breath makes a cloud in winter.», reached through the option's own match among the sentences about the question's things. What matched: the same action «make» (+3); the same thing acted on «cloud» (+2); the same property (+2). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics
Test 7 · ★★ · right ✓
Why do people put salt or grit on icy roads rather than wait for the Sun?
- 1. Salt stops the road from shrinking in the cold — no support
- 2. The Sun only makes ice thicker and harder — no support
- 3. The Sun alone often melts ice slowly — ← Mova's choice · ✓ the right answer · score 5
- 4. Salt makes the Sun shine harder on the road — no support
Why: It took the question to ask why something happens (its cause). It chose option 3 with score 5, the only option with support. Its support: lesson 6, line 15: «Sand and grit on icy paths give shoes and tyres something rough to grip, and salt melts the ice because salty water freezes at a lower temperature.», reached through the option's own match among the sentences about the question's things. What matched: the same action «melt» (+3); the same thing acted on «ice» (+2). · the question and its options parsed, with trees and pragmatics
Test 8 · ★★ · right ✓
You watch the thermometer in a glass of melting ice for ten minutes. What do you see?
- 1. It stays near 0 degrees while the ice melts — ← Mova's choice · ✓ the right answer · score 3
- 2. It rises steadily the whole time — no support
- 3. It falls lower and lower — no support
- 4. It jumps straight up to room temperature at once — no support
Why: It took the question to ask what it is done to. It chose option 1 with score 3, the only option with support. Its support: lesson 24, line 10: «Melting ice takes in lots of heat without getting warmer, so a drink with ice stays near 0 degrees until the ice is gone.», reached through the same lesson line as the sentence the question matched. What matched: the same action «stay» (+2); the same place «0 degrees» (+2). Against it: a different doer (counts against) (-1). · the question and its options parsed, with trees and pragmatics
Test 9 · ★★ · right ✓
Why is it a bad idea to put a full glass bottle of water in the freezer?
- 1. Glass melts in the freezer — no support
- 2. The freezer will stop working — no support
- 3. Water grows as it freezes and can crack the bottle — ← Mova's choice · ✓ the right answer · score 6
- 4. The water will boil in the cold and blow the cap off — no support
Why: It took the question to ask why something happens (its cause). It chose option 3 with score 6, the only option with support. Its support: lesson 12, line 5: «Water grows bigger when it freezes, because its molecules line up in an open pattern with gaps, so ice floats, and a full bottle of water left in the freezer c…», reached through the same lesson line as the sentence the question matched. What matched: the same action «grow» (+4); the same doer «water» (+2). · the question and its options parsed, with trees and pragmatics
Test 10 · ★★ · right ✓
oi, don't stick your hand over the spout, the white stuff's just mist innit. What's the truth?
- 1. It is scalding hot, and the invisible steam below it is too — ← Mova's choice · ✓ the right answer · no support
- 2. It is dust and will just make you sneeze — no support
- 3. It is cool mist and harmless — no support
- 4. Only the kettle body is hot — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 11 · ★★ · right ✓
Your dad holds a stuck jar lid under the hot tap and it opens. Which idea explains it best?
- 1. Metal grows more than glass when warmed — ← Mova's choice · ✓ the right answer · score 10
- 2. Hot water dissolves the lid — no support
- 3. Glass grows more than metal when warmed — no support
- 4. Hot water makes the jam lighter — no support
Why: It took the question to ask who or what does it. It chose option 1 with score 10, the only option with support. Its support: lesson 24, line 15: «A stuck metal jar lid opens after running it under hot water, because metal grows more than glass when warmed.», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+4); the same action «warm» (+3); the same doer «metal» (+3). · the question and its options parsed, with trees and pragmatics
Exam question 1 · formal language · wrong ✗
Identify the principal reason for which the external surface of a chilled beverage can becomes wet.
- 1. The beverage permeates the metal of the can — ← Mova's choice · no support
- 2. The metal itself liberates water — no support
- 3. Water vapour in the ambient air condenses upon the cold surface — ✓ the right answer · no support
- 4. The can is wetted by the warm hand that holds it, which perspires — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Exam question 2 · formal language · wrong ✗
Which of the following statements most accurately characterises the operation of a domestic refrigerator?
- 1. It admits cold air from outside the dwelling — ← Mova's choice · no support
- 2. It transfers heat from its interior and releases it at its rear — ✓ the right answer · no support
- 3. It generates cold from electrical energy — no support
- 4. It compresses foodstuffs in order to cool them more rapidly and evenly — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Exam question 3 · formal language · right ✓
It is given that water is enclosed in a sealed rigid vessel and frozen. State the likely consequence.
- 1. The vessel may fracture owing to the expansion of the water upon freezing — ← Mova's choice · ✓ the right answer · no support
- 2. No alteration of volume will occur — no support
- 3. The vessel will contract and remain sound — no support
- 4. The water will contract and leave a void — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Exam question 4 · formal language · right ✓
Ascertain the reason for which expansion joints are incorporated into bridges.
- 1. To accommodate the expansion and contraction of the structure with temperature — ← Mova's choice · ✓ the right answer · no support
- 2. To reduce the speed of vehicles — no support
- 3. To generate a warning sound — no support
- 4. To permit the drainage of rainwater exclusively — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/physics/24-melting-freezing-and-boiling/