---
title: Melting, freezing and boiling — how Mova does on the tests · World
description: Lesson 12 of the world course of Mova's primary school: 5 of 13 tests right, exam 2 of 4, every question with the options, the student's choice, the right answer and why it chose.
---

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# Melting, freezing and boiling

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**Tests:** 5 of 13 right · **Exam:** 2 of 4 right · **Kind:** plain · **Understood:** 5 of 17 · **Run:** 2026-10-18, commit `f3c23ea72`

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Lesson 12 of the world 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](https://md.mova.elamur.ai/free/en/corpora/school/world/12-melting-freezing-boiling/).

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Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/).

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### Test 1 · wrong ✗ {#t1}

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Red-hot lava cools and becomes rock. What change of state is this?

- **1.** Evaporating, a liquid becoming a gas — **← Mova's choice** · no support
- **2.** Melting, a solid becoming a liquid — no support
- **3.** Freezing, a liquid becoming a solid — **✓ the right answer** · no support
- **4.** Boiling, a liquid becoming a gas — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t1/)

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### Test 2 · wrong ✗ {#t2}

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An ice lolly is left in the sunshine. What happens and why?

- **1.** It turns straight into a gas — **← Mova's choice** · no support
- **2.** It melts because it takes in heat — **✓ the right answer** · no support
- **3.** It freezes harder in the bright light — no support
- **4.** It boils because the Sun is hot — no support

<!-- .why -->
**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t2/)

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### Test 3 · wrong ✗ {#t3}

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Which is true?

- **1.** Water loses its particles when it freezes — **← Mova's choice** · no support
- **2.** Melting makes a brand new substance — no support
- **3.** Ice is a different chemical from water — no support
- **4.** An ice cube and the water it melts into are the same substance — **✓ the right answer** · no support

<!-- .why -->
**Why:** Nothing it remembers matched the question, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t3/)

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### Test 4 · wrong ✗ {#t4}

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Why do water pipes sometimes burst in a very cold winter?

- **1.** The cold pipes shrink and crush the water — **← Mova's choice** · no support
- **2.** The water inside freezes and expands — **✓ the right answer** · no support
- **3.** Frost outside pushes the pipes inward — no support
- **4.** Cold water is much heavier than warm water — no support

<!-- .why -->
**Why:** Nothing it remembers matched the question, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t4/)

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### Test 5 · wrong ✗ {#t5}

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A cook wants to cook pasta faster by heating boiling water even more strongly. Why will it not get much hotter?

- **1.** The pot cannot hold water that is hotter — **← Mova's choice** · no support
- **2.** Water stops taking in heat once it bubbles — no support
- **3.** The pasta cools the water straight back down — no support
- **4.** The extra heat only turns more water into vapour — **✓ the right answer** · no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t5/)

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### Test 6 · right ✓ {#t6}

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Which of these is NOT a change of state?

- **1.** Toasting bread — **← Mova's choice** · **✓ the right answer** · no support
- **2.** Ice melting in a drink — no support
- **3.** Water freezing in a tray — no support
- **4.** Chocolate hardening in the fridge — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t6/)

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### Test 7 · right ✓ {#t7}

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Which needs the highest temperature to melt?

- **1.** Iron — **← Mova's choice** · **✓ the right answer** · score 8
- **2.** Chocolate — score 5
- **3.** Butter — score 4
- **4.** Ice — score 4

<!-- .why -->
**Why:** It took the question to ask who or what does it. It chose option 1 with score 8, against 5 for the next best. Its support: lesson 12, line 12: «Different substances melt at different temperatures: butter melts in a warm room, but iron needs about 1500 °C.», reached through the remembered sentence the question matched. What matched: the same action «need» (+4); it fills the role the question asks for (+4); the same doer «iron» (+2). Against it: a different thing acted on (counts against) (-2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t7/)

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### Test 8 · right ✓ {#t8}

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Which takes up more space: one kilogram of ice or one kilogram of liquid water?

- **1.** They take exactly the same space — score 4
- **2.** It depends on the shape of the container — no support
- **3.** The liquid water — score 8
- **4.** The ice — **← Mova's choice** · **✓ the right answer** · score 14

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**Why:** It took the question to ask who or what does it. It chose option 4 with score 14, against 8 for the next best. Its support: lesson 12, line 14: «Water expands when it freezes, so ice takes up more space than the water it came from.», reached through the remembered sentence the question matched. What matched: the same action «take up» (+4); the same thing acted on «more space» (+4); it fills the role the question asks for (+4); the same doer «ice» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t8/)

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### Test 9 · wrong ✗ {#t9}

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What do boiling and melting have in common?

- **1.** Both turn something into a solid — **← Mova's choice** · no support
- **2.** Both happen at 0 °C — no support
- **3.** Both make a new substance — no support
- **4.** Both need heat to be added — **✓ the right answer** · no support

<!-- .why -->
**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t9/)

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### Test 10 · wrong ✗ {#t10}

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wot temp does water boil at again

- **1.** About 50 °C — **← Mova's choice** · no support
- **2.** About 100 °C — **✓ the right answer** · no support
- **3.** About 0 °C — no support
- **4.** About 212 °C — no support

<!-- .why -->
**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t10/)

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### Test 11 · wrong ✗ {#t11}

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why'd the bottle crack in the freezer

- **1.** Ice weighs much more than water — **← Mova's choice** · no support
- **2.** Water shrinks and pulls the glass in — no support
- **3.** Water expands when it freezes — **✓ the right answer** · no support
- **4.** The cold makes glass melt — no support

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**Why:** Nothing it remembers matched the question, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t11/)

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### Test 12 · right ✓ {#t12}

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my sister says the bubbles in boiling water are air. true?

- **1.** No, they're water vapour — **← Mova's choice** · **✓ the right answer** · score 10
- **2.** Yes, they're air from the pan's bottom — score 10
- **3.** Yes, they're air coming out of the water — score 10
- **4.** No, they're tiny bits of ice — no support

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 10, tied with another option at 10 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 12, line 16: «The bubbles in boiling water are water vapour, not air.», reached through the remembered sentence the question matched. What matched: the same doer «bubbles» (+4); the same thing acted on «water vapour» (+4); the same light verb (be, have, do, get, go) (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t12/)

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### Test 13 · right ✓ {#t13}

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Mia says if u turn the hob up the boiling water gets way hotter than 100. right?

- **1.** Yes, more heat always makes it hotter — score 1
- **2.** No, it gets colder because it boils away — no support
- **3.** Yes, it can reach 200 °C if you wait — score 6
- **4.** No, it stays at about 100 °C, it just boils faster — **← Mova's choice** · **✓ the right answer** · score 12

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**Why:** It took the question to ask which statement is true. It chose option 4 with score 12, against 6 for the next best. Its support: lesson 12, line 11: «While water is boiling, it stays at about 100 °C however strongly it is heated.», reached through the remembered sentence the question matched. What matched: the same action «stay» (+4); the same doer «water» (+4); the same circumstance (+4). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/t13/)

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### Exam question 1 · formal language · right ✓ {#e1}

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State the temperature at which pure water freezes.

- **1.** Zero degrees Celsius — **← Mova's choice** · **✓ the right answer** · no support
- **2.** Four degrees Celsius — no support
- **3.** One hundred degrees Celsius — no support
- **4.** Minus ten degrees Celsius — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/e1/)

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### Exam question 2 · formal language · wrong ✗ {#e2}

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Whereas ice is undergoing melting, ascertain the temperature thereof until the process is complete.

- **1.** It falls steadily throughout — **← Mova's choice** · no support
- **2.** It rises steadily throughout — no support
- **3.** It fluctuates unpredictably — no support
- **4.** It remains at zero degrees Celsius — **✓ the right answer** · no support

<!-- .why -->
**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/e2/)

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### Exam question 3 · formal language · right ✓ {#e3}

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Select the response that is consistent with the established facts concerning the bubbles observed in boiling water.

- **1.** They consist of oxygen alone — no support
- **2.** They consist of water vapour — **← Mova's choice** · **✓ the right answer** · score 4
- **3.** They consist of air — score 4
- **4.** They consist of hydrogen alone — no support

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**Why:** It took the question to ask which statement is true. It chose option 2 with score 4, tied with another option at 4 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 12, line 16: «The bubbles in boiling water are water vapour, not air.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «bubbles» (+2); the same circumstance (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/e3/)

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### Exam question 4 · formal language · wrong ✗ {#e4}

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Identify the principal reason for which water boils below one hundred degrees Celsius at high altitude.

- **1.** The water contains less salt — **← Mova's choice** · no support
- **2.** The air pressure is diminished — **✓ the right answer** · no support
- **3.** The water is colder at altitude — no support
- **4.** The Sun is nearer at altitude — no support

<!-- .why -->
**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](https://md.mova.elamur.ai/free/en/corpora/questions/world/12-melting-freezing-boiling/e4/)

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- ← previous: [11. Solids, liquids and gases](https://md.mova.elamur.ai/free/en/school-run/world/11-solids-liquids-gases/)
- next →: [13. Evaporation and condensation](https://md.mova.elamur.ai/free/en/school-run/world/13-evaporation-condensation/)
- ↑ back to [World](https://md.mova.elamur.ai/free/en/school-run/world/)