Mixtures and how to separate them

Tests: 3 of 13 right · Exam: 1 of 4 right · Kind: ★★ · Understood: 8 of 17 · Run: 2026-10-18, commit f3c23ea72

Lesson 19 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.

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 ✗

Gold-seekers swirl river gravel in a pan of water. The heavy gold stays in the pan and the lighter sand washes out. Which property is used?

1. Gold dissolves in water — score 3
2. Gold floats on water — score 3
3. Gold is pulled by magnets — ← Mova's choice · score 5
4. Gold is much denser than sand — ✓ the right answer · no support

Why: It took the question to ask what it is done to. It chose option 3 with score 5, against 3 for the next best. Its support: lesson 19, line 5: «Other tricks use other properties: a magnet pulls iron out of sand, oil floats on water and can be skimmed off, and heavy bits settle to the bottom of still wa…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «magnet» (+3); the same action «pull» (+2). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 2 · ★★ · wrong ✗

A boy spills steel paper clips into a bowl of rice. How can he get them out quickly?

1. Boil the rice until it is soft — ← Mova's choice · no support
2. Pour in water and filter it — no support
3. Use a magnet — ✓ the right answer · no support
4. Dissolve the rice in water — no support

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

Test 3 · ★★ · wrong ✗

Seawater is left in a dish in the hot sunshine. Later there is a white crust. Why?

1. The Sun turned the water white — no support
2. The dish made salt of its own — ← Mova's choice · score 4
3. Frost formed on the dish — no support
4. The water evaporated and left the salt — ✓ the right answer · score 4

Why: It took the question to ask why something happens (its cause). 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 19, line 4: «Evaporating separates a dissolved solid from a liquid: the water leaves as vapour and the solid is left behind, as when salt is made from seawater.», reached through the same lesson line as the sentence the question matched. What matched: the same action «make» (+2); the same thing acted on «salt» (+2). The right option, 4, scored 4. · the question and its options parsed, with trees and pragmatics

Test 4 · ★★ · wrong ✗

A gardener wants to remove the small stones from a pile of soil. Which tool helps most?

1. A long thermometer — ← Mova's choice · no support
2. A strong magnet — no support
3. A sheet of filter paper — no support
4. A garden sieve — ✓ the right answer · 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 · ★★ · wrong ✗

Which cannot be separated by filtering?

1. Tea leaves floating in tea — ← Mova's choice · no support
2. Sand stirred into water — no support
3. Chalk dust mixed into water — no support
4. Sugar dissolved in tea — ✓ the right answer · 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 6 · ★★ · wrong ✗

Why do people let muddy water stand for a while before pouring it off carefully?

1. Standing water kills all the germs — ← Mova's choice · no support
2. The mud dissolves while it stands — no support
3. The water cleans itself in the sunshine as it stands there — no support
4. The mud settles, so clearer water can be poured off — ✓ the right answer · 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 7 · ★★ · right ✓

Which is true about a mixture of salt and pepper?

1. Each keeps its own taste and look — ← Mova's choice · ✓ the right answer · score 7
2. The pepper dissolves the salt — no support
3. They join into a new substance — score 6
4. It can never be separated — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 7, against 6 for the next best. Its support: lesson 19, line 1: «A mixture is two or more substances mixed together without becoming a new substance; each keeps its own properties, so we can separate them again.», reached through the same lesson line as the sentence the question matched. What matched: the same action «keep» (+4); the same doer «each» (+4). Against it: a different thing acted on (counts against) (-1). · the question and its options parsed, with trees and pragmatics

Test 8 · ★★ · wrong ✗

A girl wants pure water from salty water, not just the salt. What must she add to evaporating it?

1. A piece of filter paper to catch the salt as it boils — no support
2. A cold surface to catch the vapour and condense it — ✓ the right answer · no support
3. A strong magnet — no support
4. More salt — ← Mova's choice · score 5

Why: It took the question to ask a circumstance (with what, when, how). It chose option 4 with score 5, the only option with support. Its support: lesson 19, line 6: «For example, to get salt from muddy salty water you first filter out the mud, then evaporate the water to leave the salt.», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+3); the same circumstance (+2). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 9 · ★★ · wrong ✗

Why is a paper filter used when making coffee?

1. It dissolves the coffee grounds — ← Mova's choice · no support
2. It lets the liquid through and holds back the grounds — ✓ the right answer · no support
3. It makes the coffee cold — no support
4. It takes out all the coffee taste and leaves only water — 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 10 · ★★ · wrong ✗

how'd u get the sand out of the water

1. Use a magnet — no support
2. Pour it through a filter — ✓ the right answer · score 4
3. Freeze it and the sand floats — no support
4. Stir it until the sand dissolves — ← Mova's choice · score 5

Why: It took the question to ask which statement is true. It chose option 4 with score 5, against 4 for the next best. Its support: lesson 18, line 4: «Some solids dissolve in water: sugar and salt break up into particles too small to see and spread through the water, making a solution. Sand and pepper do not…», reached through the same lesson line as the sentence the question matched. What matched: the same action «dissolve» (+4); the same doer «sand» (+4). Against it: one says «not», the other does not (counts against) (-3). The right option, 2, scored 4. · the question and its options parsed, with trees and pragmatics

Test 11 · ★★ · wrong ✗

got iron filings mixed with sand, how to split em

1. Use a filter — ← Mova's choice · no support
2. Add water and boil it — no support
3. Use a magnet — ✓ the right answer · no support
4. Pour it through a fine sieve — 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 12 · ★★ · right ✓

my sister says u can get the salt out of salty water with a filter. true?

1. No, you need a magnet for salt — no support
2. Yes, a fine filter catches all the salt — no support
3. No, dissolved salt passes through; evaporate the water instead — ← Mova's choice · ✓ the right answer · score 4
4. Yes, if you filter it twice — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 4, the only option with support. Its support: lesson 19, line 6: «For example, to get salt from muddy salty water you first filter out the mud, then evaporate the water to leave the salt.», reached through a sentence linked to the one the question matched. What matched: the same action «evaporate» (+2); the same thing acted on «water» (+2). · the question and its options parsed, with trees and pragmatics

Test 13 · ★★ · right ✓

Mia says oil n water mix if u shake hard enough and stay mixed. right?

1. No, they separate again and the oil floats on top — ← Mova's choice · ✓ the right answer · score 6
2. Yes, the oil dissolves after a while — no support
3. Yes, shaking makes them one liquid — no support
4. No, the water floats on top of the oil — score 3

Why: It took the question to ask which statement is true. It chose option 1 with score 6, against 3 for the next best. Its support: lesson 19, line 13: «Oil and water do not mix; oil floats on top.», reached through a sentence linked to the one the question matched. What matched: the same action «float» (+2); the same doer «oil» (+2); the same place «top» (+2). · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · wrong ✗

Identify the appropriate method for the separation of sand from water.

1. Dissolution — ← Mova's choice · no support
2. Use of a sieve with large holes — no support
3. Filtration — ✓ the right answer · no support
4. Use of a magnet — 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 ✗

Select the response that is consistent with the established facts concerning the filtration of salt water.

1. The dissolved salt passes through the filter with the water — ✓ the right answer · no support
2. The filter converts the salt into sand — no support
3. The water is retained and the salt passes through — ← Mova's choice · score 4
4. The salt is retained upon the filter paper — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 4, the only option with support. Its support: lesson 17, line 15: «Air takes up space: push an upturned glass straight down into water and the air trapped inside keeps the water out of most of the glass.», reached through the option's own match among the sentences about the question's things. What matched: the same action «keep» (+2); the same thing acted on «water» (+2). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · wrong ✗

Identify the process by which pure water may be obtained from salt water.

1. Sieving through a fine mesh — ← Mova's choice · no support
2. Separation by means of a magnet — no support
3. Distillation, the vapour being collected and condensed — ✓ the right answer · no support
4. Filtration through fine paper — 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 ✓

Determine the appropriate method for the separation of iron filings from sand.

1. The application of a magnet — ← Mova's choice · ✓ the right answer · no support
2. The addition of water and stirring — no support
3. Filtration through paper — no support
4. Evaporation by heating — 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/world/19-mixtures-and-separating/